A cell produced by the bone marrow which, when stimulated by an antigen, becomes either a memory cell or a plasma cell that forms antibodies against that antigen. Compare T lymphocyte.
2. Babes-Ernst granules
Definition:
Particles found in some bacteria that, when the bacteria are dyed, become a different color than the dye.
3. babesiasis (babesiosis, piroplasmosis)
Definition:
A parasitic disease affecting mammals which is caused by protozoa from the genus Babesia of the order Piroplasmida and is transmitted by ticks. The Babesia protozoa feed on the blood of mammals. Symptoms include high fever, anemia, and red urine (hemoglobinuria).
4. baccate
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Berry-like; of seeds, having a succulent or pulpy testa; of fruits, having the seeds embedded in pulp.
5. bacilli
Definition:
Rod-shaped bacterial cells.
6. bacilliform (bacteriform)
Definition:
Shaped like bacteria: rodlike; elongated cylinders with rounded ends.
7. Bacillus
Author: Guo Li
Definition:
A class of bacteria which are rod-shaped. Belonging to this class are: E. coli, Salmonella, Shigella, Klebsiella, Enterobacter, Clostridia; of these, Bacillus Calmett-Guérin is administered for vaccination against tuberculosis; bacteria causing tetanus, diphtheria, pertussis, and tuberculosis are also rod-shaped.
8. bacillus (pl. bacilli)
Definition:
A rod-shaped bacterium.
9. Bacillus amyloliquifaciens
Definition:
B. amyloliquifaciens is a Gram-positive, rod-shaped bacterium used to produce alpha-amylase and serine protease.
10. Bacillus licheniformis
Definition:
B. lichemiformis is a Gram-positive, rod-shaped bacterium which is used in the biotech industry to produce the protease enzyme subtilisin.
11. Bacillus popilliae
Definition:
B. popilliae is a Gram-positive bacterium which attacks only the Japanese beetle (Popillia japonica) and is therefore used in some places in the U.S. to kill the beetles. When the larvae are infected, they turn white because of all the bacterial spores (endospores) that develop in the insects' hemolymph (blood equivalent).
12. Bacillus subtilis
Definition:
B. subtilis is a Gram-positive, rod-shaped, nonpathogenic bacterium which lives in soil. Its genome has been widely studied and is frequently used in genetic engineering and microbiology experiments.
13. Bacillus thuringiensis (Bt)
Author: Susan
A.Hagedorn
Definition:
Bacillus thuringiensis is a bacterium that kills insects (mainly in the genera Lepidoptera, Diptera and Coleoptera) and is a major component of the microbial pesticide industry. Researchers are also investigating ways to incorporate the bacterium's insect toxins into the genomes of plants to make insect-resistant crops.
14. bacitracin (Altracin, Ayfivin, Fortracin, Penitracin,
Topitracin,Zutracin)
Image:
View the chemical structure
Definition:
An antibiotic that inhibits the growth of cell walls in Gram-positive bacteria.
15. back cross
Definition:
A crossing of a heterozygous organism and one of its homozygous parents.
16. back mutation
Definition:
A mutation that causes a mutant gene to revert to its original wild-type base sequence.
This is the opposite of a forward mutation.
17. backache (back ache)
Author: Guo Li
Definition:
This is more commonly referred to as low back pain, which affects many people. It is chronic, and often precipitated by moving, lifting objects, or twisting of the waist. Bed rest often relieves it. There are many causes for low back pain, ranging from muscle spasm, disc problems, arthritis, to the spread of cancer from distant sites. The treatment also ranges from symptomatic relief with analgesics, to surgery on the lumbar vertebrae.
18. backbone
Definition:
19. backcross (back cross)
Author: ForBio Ltd.
Definition:
A population created by crossing an individual back to one of its parents. This mating design enables the comparison of the effect of the alleles contributed by one parent against the genetic background of the recurrent parent.
20. backfill
Author:
Definition:
Soil, overburden, mine waste or imported material used to replace material removed during mining.
21. backflushing
Definition:
A process used to clean filters or membranes of particles by reversing the flow of fluid through the system.
22. background retinopathy (nonproliferative retinopathy)
Author: PharmInfoNet
Definition:
Early stage of diabetic retinopathy; it usually does not impair vision.
23. backward selection
Author: ForBio Ltd.
Definition:
A situation in which the best parents in a generation are chosen for breeding on the basis of their progeny’s performance.
24. backwater
Author:
Definition:
25. backwater pool
Author:
Definition:
A pool formed by an eddy along a channel margin downstream from an obstruction such as a bar, rootwad or boulder, or by back-flooding upstream from an obstruction; sometimes separated from the channel by sand or gravel bars. Also, a body of water whose stage is controlled by some downstream channel feature, or a cove or flooded depression with access to the main stream.
26. BACON
Definition:
"Bleomycin," "Adriamycin," "CCNU (lomustin)," "Oncovin," and "nitrogen mustard": A combination of drugs used in cancer chemotherapy treatment.
27. BACOP
Definition:
"Bleomycin," "Adriamycin," "cyclophosphamide," "Oncovin," and "prednisone": a combination of drugs used as a chemotherapy treatment for malignant lymphoma.
28. BACTEC
Definition:
A commercially-done lab test which looks for microorganisms in samples of body fluids which normally do not contain any microorganisms.
29. bacteremia
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
The transient appearance of bacteria in the blood.
30. bacteremia (adj.: bacteremic)
Author: Guo Li
Definition:
A term referring to the spread of bacteria from the site of infection (a cut, for instance) to the bloodstream. Fever and chills after often associated with episodes of bacteremia.
31. Bacteria (Eubacteria)
Definition:
A super-classification (above kingdom level) of all prokaryotes; excludes Archaebacteria.
32. bacteria (sing. bacterium)
Definition:
Tiny, unicellular, prokaryotic organisms that reproduce by cell division and usually have cell walls; can be shaped like spheres, rods or spirals and can be found in virtually any enviroment.
33. bacterial conjugation
Definition:
The process of transferring a certain plasmid of DNA known as the F plasmid (or sex plasmid) from bacteria individuals who have it (known as "males") to bacteria individuals who do not already have it (known as "females") by way of direct contact between the bacteria individuals called a conjugation bridge. Once transfer is completed, the female individual becomes a male individual and both parties have a copy of the F plasmid.
34. bacterial endospore
Definition:
A dormant body which certain Gram-positive bacteria can develop within them under conditions of stress (like lack of nutrients), which is highly resistant to harsh environmental conditions and which can develop into a new, live bacterium once conditions are good again.
35. bacterial transformation
Definition:
A genetics lab procedure where bacteria are induced to accept and incorporate into their genome foreign pieces of cell-less, isolated DNA, often in the form of a plasmid. The DNA to be introduced usually contains a selectable marker so that the bacteria which successfully incorporate the DNA can be selected for.
36. bacterial transposition
Definition:
A short sequence of DNA (known as a transposon) which can change location on the bacterial genome (the sum total of all of the bacterium's DNA) and contains genes which code for proteins that enable it to change location. They are useful because they can also contain genes for other things, like antibiotic resistance, and because they can be introduced into a bacterial genome by a researcher.
37. bacterial virus (bacteriophage)
Definition:
38. bacterial wilt disease
Definition:
A plant disease common in cucumber and muskmelon caused by the bacteria Erwinia tracheiphila which causes wilting and shriveling of the stems and leaves.
39. bactericidal
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
Capable of killing bacteria.
40. bactericidal (bactericide)
Author: Guo Li
Definition:
Pertaining to the killing of bacteria. A term often used to describe the property of antibiotics. However, it is now known that the effectiveness of drug action depends on more than whether or not the antibiotic "kills" bacteria in experiments conducted on petri dishes. First the drug has to reach the tissue compartment where its action is needed, e.g. the mid-ear, in the case of otitis media. Second, the elimination of bacteria is also dependent on the availability of functioning white cells, and on other components of the immune system. Therefore many immunologically compromised patients do not do well against an infection despite the administration of potent antibiotics.
41. bacterin
Definition:
A vaccine composed of weakened or dead bacteria which will cause the body to create antibodies against the disease normally caused by the bacteria in the vaccine.
42. bacteriochlorophyll
Definition:
A pigment, or colored particle, found in bacteria that anaerobically photosynthesizes (uses the sun as a source of energy), the way green pigments of chlorophyll found in plants photosynthesize.
43. bacteriochlorophyll
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
The light-absorbing pigment found in green sulfur and purple sulfur bacteria. Compare chlorophyll.
44. bacteriocin
Definition:
A substance that certain bacteria can release which kills closely-related strains of other bacteria, but without rupturing their cell membranes.
45. bacteriocinogen
Definition:
A plasmid, or ring of DNA, found in certain bacteria which controls the production of bacteriocin, a substance that the bacteria can use to kill closely-related strains of other bacteria without rupturing their cell membranes.
46. bacteriocyte
Definition:
A modified fat cell found in certain insects which contain groups of rod-shaped objects thought to be symbiotic bacteria.
47. bacteriogenic
Definition:
Something that bacteria have produced or caused.
48. bacterioid (bacteriodal)
Definition:
Something which looks like a bacterium.
49. bacteriological warfare
Definition:
Use of harmful bacteria by the military as weapons against the enemy.
50. bacteriologist
Definition:
A scientist who studies bacteria.
51. bacteriology
Definition:
The scientific study of bacteria.
52. bacteriology
Definition:
The study of a group of single-celled procaryotic organisms called bacteria.
53. bacteriophage lambda
Definition:
A bacteriophage (a virus which infects bacteria) that infects E. coli. It has a complex set of regulatory mechanisms to determine whether it will quietly insert its DNA into the bacterial genome to become dormant and to be reproduced whenever the bacterium reproduces (to lysogenize), or whether it will hijack the bacterium's cellular machinery to reproduce itself and prepare to infect more bacteria, causing the bacterium to self-destruct shortly after infection (to lyse). Lambda is particularly useful to geneticists because parts of it can be used to introduce foreign DNA into the bacterial genome; it is a cloning vector.
54. bacteriophage M13
Definition:
A bacteriophage (a virus which infects bacteria) that has single-stranded DNA. It is used as a method of obtaining single strands of foreign DNA so that the foreign DNA can be sequenced (that is, the order of its nucleotide bases can be determined). It is also used in procedures to create mutations in vitro (in a test tube rather than within an organism).
55. bacteriophage omicron X174
Definition:
A bacteriophage (a virus that infects bacteria) which has as its genetic material DNA in single strands instead of the usual double strands. The virus is useful to those who study how DNA replicates.
56. bacteriophage T4
Definition:
A bacteriophage (a virus which infects bacteria) which uses DNA as its genetic material (some viruses use RNA) and is unusually large.
57. bacteriophage T7
Definition:
A bacteriophage (a virus which infects bacteria) that is useful to geneticists because it has a very strong promoter region which strongly encourages transcription of its gene by specific T7 RNA polymerase. Geneticists can take the part with the promoter and attach their own genes of interest to it so that they can control transcription rates of their gene by choosing the amount of the RNA polymerase to put in.
58. bacteriophytoma
Definition:
A lesion resembling a tumor that is caused by bacteria.
59. bacteriorhodopsin
Definition:
A pigmented protein embedded in the cell membrane of the bacteria Halobacterium halobium (and other photosynthetic species of bacteria). The protein transports protons across the cell membrane, and its effectiveness (and thus the bacterium's effectiveness at making energy) depends on the amount of light it receives.
60. bacteriostasis
Definition:
The prevention of bacteria from growing, but without killing them.
61. bacteriostat (bacteriostatic agent)
Definition:
A substance which stops bacteria from growing, but does not kill them.
62. bacteriostatic
Definition:
A compound that prevents bacteria from multiplying.
63. bacteriostatic
Author: Guo Li
Definition:
Pertains to the arresting of the growth of bacteria. A term often used to describe the property of antibiotics. Sometimes, a bacteriostatic antibiotic is more effective than an bactericidal antibiotic, for the reasons described under the term bactericidal.
64. bacteriotoxin
Definition:
65. bacteriotropin
Definition:
Something which combines with bacteria, such as an antibody, so that the bacteria becomes more likely to get destroyed by its host's immune system.
66. bacteriuria
Author: Guo Li
Definition:
The condition of finding bacteria in the urine. Under normal circumstances fresh urine excreted from the kidney is sterile. However, when urine passes through the urethra, it picks up a small amount of bacteria. Bacteriuria with 100,000 bacteria per ml. is highly suggestive of infection in the urinary tract.
67. bacteroid
Definition:
68. Baculoviridae
Definition:
The family name for a group of viruses which infect insects. There is only one genus within the family: Baculovirus.
69. Baculovirus
Definition:
A genus of viruses which infect insects. They are used to control insects. They are also used to make proteins with polysaccharides (sugar chains) attached from cloned DNA, something which does not happen when proteins are made from cloned DNA using bacteria.
70. baffle
Author:
Definition:
A pier, vane, sill, fence, wall, or mound built on the bed of a stream to parry, deflect, check, or disturb the flow or to float on the surface to deflect or dampen cross currents or waves.
71. balanced chromosome
Definition:
A chromosome which is unable to pair with its homologue and participate in homologus recombination during meiosis because it contains several inversion mutations (that is, has segments which have become flip-flopped).
72. balanced lethal system
Definition:
A population with non-linked, recessive alleles of a gene, where an individual who has two copies of the recessive allele and is therefore homozygous is dead, while an individual who has only one copy of it, and one copy of a different allele (and is heterozygous) survives.
73. balanced polymorphism
Definition:
A type of polymorphism where the many morphs are alleles. The polymorphism is maintained in a population rather than the norm of one allele eventually becoming the only allele in the population, because individuals who are heterozygous, or have two different alleles, are more adaptive (more "fit") than individuals who are homozygous, or have two copies of the same allele.
74. balanced stock
Definition:
A genetic strain of any of several lab organisms (like fruit flies) which can be maintained as heterozygous individuals without requiring constant artificial selection for the heterozygotes, due to a number of lethal recessive genes with the result that thehomozygous females are sterile (unable to produce offspring) and the males with the wrong recessive alleles are dead. (Male fruit flies are not homozygous or heterozygous because they only have one allele per particular genetic loci in question).
75. balanced translocation
Definition:
A number of the chromosomal mutations called translocations, where a segment of DNA abnormally becomes attached to the wrong chromosome, which results in two nonhomologous chromosomes being able to cross over, something which normally can occur only between homologous chromosomes.
76. balancing selection
Definition:
A process of natural selection where heterozygous individuals are more adaptive, and thus selected for more often, than either of the two types of homozygous individuals.
77. balanitis
Author: Guo Li
Definition:
Inflammation of the glans penis.
78. Balbiani rings (chromosome puffs)
Definition:
Giant puffs on a polytene chromosome in the salivary glands of certain insect larvae which, when present, means that transcription of DNA is taking place. The puffs are areas where the chromosome has become decondensed for the purpose, and are easily visible with a light microscope.
79. balloon angioplasty (percutaneous transluminal coronary angioplasty,
PTCA)
Author: Guo Li
Definition:
This is a surgical procedure for the opening up of a narrowed or occluded coronary artery. It is a procedure for relieving angina and improvement of the patient's ability to exercise. It is successful in about 60% of the cases.
Under local anesthesia and sedation, a small incision is made in the groin area so that a thin tubing with a balloon tip can be introduced. An x-ray machine is used to help the operator to guide the balloon tip into the blood vessels of the heart. When the balloon tip reaches its destination (the occluded vessel), the operator expands the balloon tip, which then dilates the occluded vessel.
If the angioplasty is not desired by the patient, the physician can continue drug treatment if this is still to some extent effective. However, it may be that balloon angioplasty is recommended exactly because of the failure of drug treatment. Another alternative is open heart surgery for aorto-coronary bypass (A-C bypass), also known as coronary artery bypass surgery (CABG).
The risks and side effects of this surgery can include anesthesia risks, bleeding, coronary artery dissection or intimal tear, occlusion of the blood vessel because of blood clots, irregular heart beat, heart attack, stroke, pericardial tamponade, need for emergency surgery, and recurrence of angina despite initial relief.
Local vascular complications at the site of puncture include arterial thrombosis, arterial laceration or dissection, pseudoaneurysm, hematoma, and a-v fistula. The consequences of not having the treatment include continued angina, plus the possibility of suffering a heart attack and its consequences.
80. Baltimore, David
Definition:
Born 1938. An American molecular biologist and virologist who won the Nobel Prize in 1975 for discovering that retroviruses (a group of viruses that uses RNA to code their genomes instead of DNA) make the enzyme "reverse transcriptase," which is used to make DNA copies of RNA templates. This is useful to the retrovirus who is trying to reproduce with host cellular machinery. More important, this is very useful to molecular biologists and genetic engineers who want to work with RNA molecules using DNA-manipulating techniques.
81. Bam islands
Definition:
Areas of DNA which do not get transcribed, consisting of many repeats of the same sequence of nucleotide bases.
82. band III protein
Definition:
A protein embedded in the surface of the red blood cell which, when the red blood cell is in the lungs, brings Cl- (chlorine ion) into the cell in exchange for HCO3-.
83. bank
Author:
Definition:
84. barbellae
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Short, straight, stiff hairs or barbs.
85. barbellate
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
Covered, usually laterally, with fine, short points or barbs.
86. barbulae
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Outgrowths on the margin of a seed's wings or in the throat of the corolla; they may be simple or have apical hairs or papillae.
87. barium study
Author: Guo Li
Definition:
Barum is opaque to x-ray. In a barium study, the gastrointestinal (GI) tract is filled with barium before an x-ray is taken.
Upper GI Series:
Barium Enema:
88. bark
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
The outermost covering of trees and some plants. This is composed of the cuticle or epidermis, the outer bark (cortex), and the inner bark or fiber.
89. barometer
Definition:
An instrument that measures the pressure of the atmosphere.
90. barophile
Definition:
A microorganism which grows best (or can only grow) in high-pressure environments,such as deep-sea environments.
91. barotolerant (baroduric)
Definition:
A microorganism which grows best in environments with standard atmospheric pressure, but can also survive and grow in high pressure environments.
92. Barr body
Definition:
A condensed X chromosome found in the somatic cells (all of the cells of a multicellular organism which are not sex cells) of females, visible when the nucleus of the somatic cell is not dividing. None of its genes are used, so it is inactive.
93. basal
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
At the base of a structure.
94. basal
Definition:
Having to do with the base, the bottom, the foundation, etc. of something. Something essential, vital, primary. The minimum required rate or other value for something to function.
95. basal area
Author:
Definition:
The cross-sectional area of a tree trunk measured in square inches, square centimeters, etc.; basal area is normally measured at 4.5 feet above ground level and is used as a measure of dominance; the most commonly used tool for measuring basal area is a diameter tape or a D-tape (then convert to basal area).
96. basal body (blepharoplast)
Definition:
The cylinder-shaped structure at the base of a cilium or flagellum, containing sets of microtubules. Resembles a centriole in structure.
97. basal body temperature (BBT)
Author: Fertilitext
Definition:
The temperature taken at its lowest point in the day, usually in the morning before getting out of bed.
98. basal cell carcinoma (basaloma, hair matrix carcinoma)
Definition:
An epithelial (skin) cancer that doesn't usually metastasize but can invade adjacent tissues.
99. basal lamina
Definition:
A thin layer of noncellular proteins and other noncellular stuff that is underneath the epithelium (the top layer of skin cells, also the innermost layer of cells in various vessels, the digestive and other tracts, etc.) and that the epithelium makes.
100. basal medium
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
A(n) (unsupplemented) medium which promotes the growth of many types of microorganisms which do not require any special nutrient supplements.
101. basal metabolic rate
Definition:
The rate at which an animal body consumes oxygen when it is at rest and is not digesting a meal.
102. basal metabolic rate (BMR)
Author: Guo Li
Definition:
The amount of energy liberated per unit time (metabolic rate) determined at as complete mental and physical rest as possible, in a room at a comfortable temperature, 12 hours after the last meal. The BMR of a man of average size is about 2000 food calories per day. BMR is lower in elderly subjects both on an absolute basis and per unit body weight. BMR falls by about 10% between 20 to 60 years of age. However, if the changes in body composition that comes with aging is taken into consideration, the BMR of the elderly may not be that much lower.
103. basal rate
Author: PharmInfoNet
Definition:
Refers to a continuous supply of low levels of insulin, as in insulin pump therapy.
104. base
Author: ForBio Ltd.
Definition:
Any basic (alkaline) compound containing nitrogen, but generally referring to one of four complex molecules ( nucleotides) that form the building blocks of the nucleic acids, DNA and RNA.
105. base (alkali, Bronsted base, Arrhenius base, Lewis base)
Definition:
A fundamental category of many compounds whose water-based solutions have a bitter taste, a slippery feel in water, turn red litmus paper blue, and can react with acids to form salts. A base has a pH higher than 7; a strong base will have a pH of 13 or higher. Specific types of bases include:
106. base analog
Definition:
A chemical which resembles a nucleotide base. A base which does not normally appear in DNA but can substitute for the ones which do, despite minor differences in structure.
107. base composition
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
In reference to nucleic acid, the proportion of the total bases consisting of guanine plus cytosine or thymine plus adenine base pairs. Usually expressed as a guanine + cytosine (G+C) value, e.g. 60% G+C.
108. base dissociation constant (base ionization constant)
Definition:
This is the equilibrium constant for the reaction in which a weak base breaks apart in water to form its conjugate acid and hydroxide (-OH) ion.
109. base flow (sustaining flow, normal flow, ordinary flow, groundwater
flow)
Author:
Definition:
The portion of the stream discharge that is derived from natural storage (e.g., groundwater outflow and the draining of large lakes and swamps or other source outside the net rainfall that creates surface runoff); discharge sustained in a stream channel, not as a result of direct runoff and without the effects of regulation, diversion, or other works of man.
110. base pair (bp)
Definition:
Two nitrogenous bases (adenine and thymine or guanine and cytosine) held together by weak bonds. Two strands of DNA are held together in the shape of a double helix by the bonds between base pairs.
111. base sequence
Definition:
The order of nucleotide bases in a DNA molecule.
112. base sequence analysis
Definition:
A method, sometimes automated, for determining the base sequence.
113. base substitution
Definition:
One nucleotide base is replaced by another in a DNA molecule. This is also called a point mutation.
114. baseline
Author:
Definition:
A line, generally a highway, unimproved road or some other evident feature, from which sampling transects extent into a site for which a jurisdictional wetland determination is to be made.
115. basic anhydride
Definition:
A chemical (usually the oxide of a metal) which forms a base when it's mixed with water.
116. Basidiomycetes (club fungi)
Image:
shitake mushrooms
Definition:
A class of true fungi more commonly known as club fungi, so called because they produce their spores at the tips of swollen hyphae that look a bit like clubs or baseball bats. This division includes mushrooms, puffballs, earth stars, stinkhorns, bracket fungi, rust, smuts, jelly fungi and bird's-nest fungi.
117. basifixed
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Attached at or by the base, e.g. of anthers, by the base of the connective.
118. basin
Author:
Definition:
119. basipetal
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
120. basiscopic
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Pointing towards the base (applied to the first lateral vein of a leaflet on the side nearer the leaf base).
121. basophil
Definition:
A granulocyte that has a two-lobed nucleus and is easily stained by basic dyes.
122. basophil (basiphil)
Definition:
123. batch culture
Definition:
A closed system culture of microorganisms with specific nutrient types, temperature, pressure, aeration, and other environmental conditions, where only a few generations are allowed to grow before all nutrients are used up. Batch culture is the opposite of continuous culture.
124. bathyphyll
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A leaf at the base of a stem with the function of attachment to a substrate.
125. Batten disease
Definition:
This congenital disorder strikes between the ages of 5 and 10, causing the afflicted child to suddenly go blind. The child begins to suffer from seizures and mental deterioration; afflicted individuals typically die before the age of 20. The disease is caused by the accumulation of toxic proteins in nerve cells; the root of the disorder is a mutation of a gene on chromosome 16.
126. bay
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
A part of a sea or lake indenting the shore line; the word is often applied to very large tracts of water around which the land forms a curve, as Hudson's Bay.
127. bayou
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
A marshy inlet or outlet of a lake, river, etc.; also a backwater.
128. beaded stream
Author:
Definition:
A stream consisting of a series of small pools or lakes connected by short stream segments.
129. Beadle, George W.
Definition:
b. 1903, d. 1991. An American geneticist who won the Nobel Prize in 1958 with Edward Tatum for showing that genes are responsible for controlling the production of enzymes.
130. beak
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A prominent terminal projection, especially of a carpel or fruit.
131. bechic
Definition:
A drug that stops a cough.
132. becquerel (Bq)
Definition:
This is the standard international unit of radioactive disintegration; it is represented as one disintegration per second.
133. bed
Author:
Definition:
134. bedform roughness (bed roughness)
Author:
Definition:
Measure of the irregularity of streambed materials that contributes resistance to streamflow. Commonly represented by Manning's roughness coefficient.
135. Beer-Lambert law
Definition:
The equation A=ECL, where A is the absorbance at a given wavelength of light, E is the molar extinction coefficient, C is the concentration of the molar solution, and L is the length of the light path. In words, the equation means that the concentration of a substance in moles is proportional to the absorption of a given wavelength of light by a solution of the substance. The equation is used in the study of spectroscopy.
136. Behçet's syndrome
Author: Guo Li
Definition:
Behçet's syndrome consists of recurrent ulcerations of the of mouth (usually the first sign of this syndrome), esophagus, genitals, uveitis, iritis, conjunctivitis, seronegative arthritis, and optic neuritis.
137. belching
Author: Guo Li
Definition:
Belching is the usually involuntary escape of gas from the stomach through the mouth.
138. Bence-Jones protein
Definition:
A protein found in the urine of people who have multiple myeloma, or bone marrow tumors. The protein is an antibody fragment.
139. bench mark
Author:
Definition:
A fixed, more or less permanent reference point or object of known elevation; the U.S. Geological Survey (USGS) installs brass caps in bridge abutments or otherwise permanently sets bench marks at convenient locations nationwide; the elevations on these marks are referenced to the National Geodetic Vertical Datum (NGVD), also commonly known as mean sea level (MSL); locations of these bench marks on USGS topographic maps are shown as small triangles; since the marks are sometimes destroyed by construction or vandalism, the existence of any bench mark should be field verified before planning work which relies on a particular reference point; the USGS or local state surveyors office can provide information on the existence, exact location and exact elevation of bench marks.
140. benign
Definition:
Refers to a tumor that is non-cancerous; its cells do not proliferate, nor do they invade surrounding tissues.
141. benign neoplasm
Author: Guo Li
Definition:
This is a neoplasm made up of cells that have no potential to spread to and grow in another location in the body.
142. benign prostatic hyperplasia (BPH)
Author: Guo Li
Definition:
Benign prostatic hyperplasia is a common, noncancerous condition of men above 50 years old (it affects about 30 to 50% of older men). The enlarged prostate (a walnut-sized gland at the base of the penis) obstructs the urethra (the small tube that carries urine from the bladder) and causes frequent urination.
143. benthos
Author:
Definition:
Animals and plants living on or within the substrate of a water body (freshwater, estuarine or marine).
144. benzodiazepam (Clonazepam, etc.)
Definition:
Any of several chemically related drugs that are powerful sedatives and hypnotics. They are mainly used to treat insomnia and anxiety. Side effects can include impaired motor coordination, amnesia, intoxication, and possible drug dependence. Persons who take this drug and then stop may also experience rebound, a return of symptoms that are temporarily worse than the original symptoms.
145. benzoic acid
Definition:
A white, crystalline, aromatic acid (C7H6O2) that is used as an antibacterial and antifungal agent and as a food preservative. It is a chemical precursor to the artificial sweetener saccharin.
146. benztropine (Cogentin)
Definition:
This prescription drug is used to treat Parkinson's syndrome.
147. berberine (berberin)
Definition:
A toxic organic substance with the chemical formula C20H19NO5 which is found in the roots of certain plants such as barberry and golden seal. It kills amoebas (is an amebicide) and is used to treat cholera. It cannot be dissolved in water, but is soluble in alcohol and ether. It has a melting point of 145 degrees Celsius when dry. As a solid, it is a white to yellow crystalline alkaloid.
148. Berg, Paul
Definition:
An American biochemist born in 1926, who won the Nobel Prize for developing a DNA mapping method. Also he determined that it takes two steps to oxidize fatty acids.
149. berm
Author:
Definition:
150. berry
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A fleshy or pulpy indehiscent fruit with the seed(s) embedded in the fleshy tissue of the pericarp. Compare drupe, pyrene.
151. beta blocker (beta-adrenergic antagonist)
Definition:
Any compound that blocks the activity of beta-andrenergic receptors in the sympathetic nervous system; these are often used to treat angina (chest pain) and high blood pressure.
152. Beta carotene (ß carotene)
Image:
View the chemical structure
Definition:
A carotenoid pigment that gives a reddish color to plants such as carrots and tomatoes. It is often used as a vitamin supplement because the body can convert it into Vitamin A.
153. beta cell
Author: PharmInfoNet
Definition:
A type of cell in the pancreas in areas called the islets of Langerhans. Beta cells make and release insulin, a hormone that controls the level of glucose (sugar) in the blood.
154. Beta conformation (ß conformation)
Definition:
A polypeptide chain (often a secondary structure of a protein) arranged as a long zig-zag.
155. Beta DNA (ß DNA)
Definition:
The normal form of DNA found in organisms, which exists as a right-handed helix.
156. beta human chorionic gonadotropin (beta hCG)
Author: Guo Li
Definition:
This is a glycoprotein composed of two subunits and secreted by the placenta. It is detectable 1 day after implantation of the a fertilized ovum and peaks at 60 to 90 days of gestation.
Normal level is less than 5 mIU/mL; 20-100 IU/L 1 to 2 weeks after conception and 50,000 IU/L about 65 days after pregnancy then declines. In molar pregnancy, it can be extremely high initially, (over 100,000 IU/L) but declines with time.
Normal Ranges: (in IU/L)
non-pregnant: 0 - 5
possibly pregnant: 5 - 25
During Gestation:
0 - 1 wk: 5 - 50
1 - 2 wks: 50 - 500
2 - 3 wks: 100 - 1,000
3 - 4 wks: 500 - 6,000
1 - 3 months: 5,000 - 200,000
2nd trimester: 3,000 - 50,000
3 rd trimester: 1,000 - 50,000
In the first three weeks of a normal pregnancy, the serum beta hCG approximately doubles every two days. The doubling time of hCG is considered a more reliable method of evaluating an early pregnancy than a single result.
157. Beta oxidation (ß oxidation)
Definition:
The oxidative breakdown of fatty acids into acetyl-coenzyme A by repeated oxidation at the ß-carbon atom.
158. beta particle
Definition:
An electron or positron emitted from a radioactive nucleus during beta decay.
159. beta thalassemia
Author: Guo Li
Definition:
This form of thalassemia is due to point mutations, further subdivided according to pathogenesis:
160. beta thalassemia (Cooley's anemia)
Definition:
One of two major types of thalassemia, a genetically inherited disease, where one of the two types of polypeptides making up the hemoglobin protein is defective or missing. Hemoglobin proteins are composed of four polypeptides -- two "alpha chains" and two "beta chains". In beta thalassemia, the beta chains are defective or missing (see also alpha thalassemia).
The three classifications of beta thalassemia, in order of increasing severity, are thalassemia minor, thalassemia intermedia, and thalassemia major. Thalassemia major is also known as Cooley's anemia. Symptoms include slow growth, jaundice, enlarged heart, liver, and spleen, thinned bones. Untreated children die young, usually of heart failure or infections. Thalassemia intermedia produces milder symptoms for the first two decades of life in most cases. Thalassemia minor may not produce any symptoms, though changes in the blood occur.
For more information, read this March of Dimes Public Health Info Sheet.
161. beta-amyloid
Definition:
The protein which forms thick deposits, or plaques, in the brains of people with Alzheimer's disease, a disease where memory skills gradually deteriorate with age.
162. betadine
Definition:
A type of skin disinfectant.
163. betulinic acid
Definition:
This pentacyclic terpene is found in the bark of birch trees, especially the white birch (Betula alba). It is currently being investigated as a treatment for malignant melanoma.
164. BglII
Definition:
A restriction enzyme that cuts DNA in a staggered manner wherever it finds the sequence "AGATCT."
165. bi-
Definition:
A prefix meaning "two" or "twice."
166. bicoid genes
Definition:
A group of genes which are important to the proper development of the head and thorax in the embryo of the fruit fly Drosophila melanogaster.
167. bidirectional replication
Definition:
A type of DNA replication where replication is moving along in both directions from the starting point. This creates two replication forks, moving in opposite directions.
168. biennial
Definition:
Refers to a plant that completes its life cycle in two years.
169. biennial
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A plant whose life span extends for more than one but less than two years after germination.
170. bifacial
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
171. bifid
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Divided, for about half the length, into two parts. Compare bipartite.
172. bifoliate
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Of plants: having two leaves.
173. bifoliolate
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Refers to leaves that have two leaflets.
174. bifurcation
Definition:
175. bilabiate
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Two-lipped, e.g. of a corolla in which fusion of an anterior group and a posterior group of petals extends beyond the top of the corolla tube.
176. bilateral
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
Having two sides.
177. bilateral mastectomy
Definition:
The surgical removal of both breasts.
178. bilateral symmetry
Definition:
Describes an organism which is divisible into equal mirror halves in one plane only.
179. bile
Definition:
A dark fluid containing bile salts which is secreted by the liver into the bile ducts and the gallbladder.
180. bile duct (biliary tree)
Definition:
The tubes which carry bile from the liver to the small intestine (duodenum).
181. bile salts
Definition:
Amphipathic compounds that aid digestion and lipid absorption; they are derived from steroids and have some detergent properties.
182. biliary atresia
Author: Guo Li
Definition:
Most commonly presents as complete failure of the development of all extrahepatic biliary structures.
183. biliary cirrhosis
Author: Guo Li
Definition:
A chronic disease of the liver characterized by the autoimmune destruction of the organ. Patients affected are usually women from 40-60 years of age.
184. biliary endoprosthesis
Definition:
A tube inserted into a narrowed or blocked bile duct to improve bile flow.
185. bilirubin
Definition:
A red-orange pigment found in bile which is formed when old red blood cells are broken down in the liver. It can also form from other types of heme catabolism. It has the chemical formula C33H36N4O6. It is transformed from the green bile pigment biliverdin, which is directly formed from heme catabolism. Excessive bilirubin in the blood results in jaundice.
186. bilirubin
Author: Guo Li
Definition:
Bilirubin is the by-product of breaking down hemoglobin that is measured in a blood sample. The unconjugated form of bilirubin is also called indirect bilirubin. After the liver adds a glucuronide to the unconjugated bilirubin, it is called conjugated bilirubin, also called direct bilirubin. Conjugated bilirubin is excreted into the hepatic ducts, the common bile duct and then the bowel. Serum levels of bilirubin increase when there is excessive breaking down of red blood cells, or when there is liver dysfunction. Jaundice is clinically recognizable when total bilirubin exceeds 50 umol/liter.
Normal ranges:
Total bilirubin 5.1-17.0 umol/L (adult) and 17-20 umol/L (newborn)
Indirect bilirubin 3.4-12.0 umol/L
Direct bilirubin 1.7 - 5.0 umol/L
187. biliverdin (dehydrobilirubin)
Definition:
A green pigment found in bile which is formed during heme catabolism, mainly the breaking down of old red blood cells, within the liver. It has the chemical formula C33H34N4O6. It transforms into the red-orange bile pigment bilirubin.
188. bilocular
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Having two cavities.
189. binary acid
Definition:
This refers to any compound that acts as an acid and which is composed of hydrogen plus only one other element.
190. binary compound
Definition:
This refers to any compound that is composed of only two elements.
191. binary fission
Definition:
Division of a cell into two daughter cells after DNA replication and nuclear division (mitosis). A form of asexual reproduction.
192. binding energy
Definition:
Energy generated by the noncovalent interactions between a ligand and receptor or enzyme and substrate.
193. binomial nomenclature
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
The system of having two names (genus and specific epithet, also called Latin binomial) for each organism.
194. bio-
Definition:
A prefix indicating that the word has something to do with life, living things, or the science of biology.
195. Bio-beads S
Definition:
Polystyrene beads used to fractionate molecular compounds in gel filtration chromatography with lipophilic solvents.
196. bioaccumulation
Author:
Definition:
The process by which organisms absorb chemicals or elements directly from their environment.
197. bioaccumulation factor
Author:
Definition:
Concentration of a chemical in living tissue divided by its concentration in the animal's diet.
198. bioacoustics
Definition:
The study of how organisms make and hear sounds, and how sounds affect them physically and behaviorally.
199. bioaeration
Definition:
A technique of purifying sewage by oxidizing it in centrifugal pumps.
200. bioaffinity sensor
Definition:
A sensor that uses immobilized hormone receptors or antibodies to detect hormones or antigens.
201. bioassay
Definition:
202. bioastronautics
Definition:
The study of the effects of space travel on living things.
203. bioaugmentation
Author: Susan
A.Hagedorn
Definition:
Increasing the activity of bacteria that break down pollutants; a technique used in bioremediation.
204. bioautography
Definition:
A chemistry lab technique to determine the concentration of a chemical substance such as vitamins or antibiotics by observing its effects on different test organisms' growth rates. A type of bioassay.
205. bioavailability (adj. bioavailable)
Definition:
How metabolically available a drug or other chemical becomes to the target tissue after it's introduced into a person's body.
206. bioblast
Definition:
An elementary unit of protoplasm. A formative cell.
207. bioburden
Definition:
The number of contaminating microbes on a certain amount of material prior to that material being sterilized.
208. biocatalyst
Definition:
A substance which catalyzes biochemical processes in living things. The most well-known example is the enzyme.
209. biocenology (cenobiology, biocoenology)
Definition:
A field of ecology which deals with the study of communities of organisms and the interactions and relationships between the member organisms.
210. biocenosis (biocoenosis)
Definition:
211. biochemical mechanism
Definition:
This is the general term for any chemical reaction or series of reactions, usually mediated by enzymes, which produce a given physiological effect in a living organism.
212. biochemical oxygen demand
Definition:
The amount of oxygen aerobic organisms need to carry out oxidative metabolism in water containing organic matter, such as sewage.
213. biochemistry
Definition:
The scientific study of the chemistry of living cells, tissues, organs and organisms.
214. biochemorphology
Definition:
The scientific study of the chemical structure of pharmaceuticals and nutrients and their effect on organisms.
215. biochip
Definition:
An electronic device that uses organic molecules to form a semiconductor.
216. biochrome
Definition:
A natural pigment produced by an organism.
217. biocide
Definition:
218. bioclimatology (bioclimatics)
Definition:
A field of ecology which studies the effects of climate on what plants and animals are like, physically and behaviorally.
219. biocompatibility
Definition:
The ability to exist alongside living things without harming them.
220. bioconcentration factor (BCF)
Author:
Definition:
Concentration of a chemical in an organism divided by its concentration in the test solution or environment (e.g., concentration in fish divided by concentration in water).
221. bioconversion
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
In industrial microbiology, the use of microorganisms to convert an added chemical to a chemically modified form.
222. biocybernetics
Definition:
The study of how communication and control occurs within the bodies of living things, between different parts of the body.
223. biocycle
Definition:
A biological cycle; repeated cycles of biological phenomena within the bodies of living things. Examples: menstruation in humans, the daily sleep cycle which, when disturbed, results in jet lag, and migration.
224. biocytin
Definition:
225. biocytinase
Definition:
An enzyme which converts biocytin into biotin (one of the B vitamins) and lysine (an amino acid).
226. biodegradable
Definition:
Able to be decomposed by natural biological processes, such as by being digested by bacteria or fungi.
227. biodegradation (to biodegrade)
Definition:
The degradation, or destruction of, a chemical substance or substances by biological means (such as through microorganisms using it as a nutrient).
228. biodiversity
Definition:
The existence of a wide range of different types of organisms in a given place at a given time.
229. bioelectricity
Definition:
The naturally-occurring electrical currents which flow within nerves and muscles.
230. bioelectronics
Definition:
The study of how electrons are transferred between molecules during biological regulation or biological defense. The movement of electrons is fairly important to the study of metabolism mechanisms.
231. bioenergetics
Definition:
A scientific field that deals with the application of thermodynamic principles to organisms and biological systems.
232. bioengineering
Definition:
233. bioenrichment
Author: Susan
A.Hagedorn
Definition:
Adding nutrients or oxygen to increase microbial breakdown of pollutants.
234. bioequivalence
Definition:
Two different drugs which have the same potency and bioavailability, assuming equal doses.
235. biofeedback
Definition:
Information about certain bodily functions that are normally involuntary, such as pulse rate and blood pressure, that is given to an individual so that she or he can learn to affect or control them.
236. biofeedback
Definition:
A technique that allows a person to control, via methods such as visualization and relaxation, internal processes (such as heartbeat, blood pressure, brain wave activity. etc.) that are normally outside conscious control.
237. biofilm (microbial mat)
Definition:
238. bioflavonoid
Definition:
A group of chemical substances found in many plants which help keep the cell walls of small blood vessels permeable.
239. biofuel
Definition:
A gaseous, liquid, or solid fuel that is rendered from raw biological material (plants, sewage, dry waste, etc.) through combustion or fermentation.
240. biogas
Definition:
A gas that is produced through anaerobic respiration; it contains mostly methane and carbon dioxide with small amounts of water vapor, nitrogen, hydrogen, or other gases.
241. biogenesis
Definition:
The theory that life always arises from previously existing life, and never from things which are not alive (as would be the case for the theory of spontaneous generation).
242. biogenetic law (recapitulation theory, "ontogeny recapitulates
phylogeny")
Definition:
The theory that "ontogeny recapitulates phylogeny," which means that one can trace the evolutionary development of a species by studying the development of an individual embryo or young of that species. The theory is still used, especially in paleontology, but has been found to not be strictly true when applied to problems in biology.
243. biogenetics
Definition:
A form of genetic engineering; the science of adding or altering the genetic code of an organism to achieve particular traits. This technique is becoming more and more important in agriculture as researchers seek to make crops that are resistant to pests.
244. biogenic
Definition:
245. biogenic amine (bioamine)
Definition:
A group of chemical substances which are made by cells and which alter various bodily functions (like vascular functions or nervous system functions).
246. biogeochemistry
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
Study of microbially-mediated chemical transformations of geochemical interest, e.g. nitrogen or sulfur cycling.
247. biogeography
Definition:
The study of the distribution of different species of organisms around the planet and the factors that influenced that distribution.
248. biogeotechnology
Author:
Definition:
The use of biological, ecological, and geotechnical engineering data to solve geological problems (such as erosion). Applied biogeotechnology focuses on using plants and human-made structures to control erosion, protect slopes, and restore environmental quality.
249. biohazard
Definition:
A risk of exposure to harmful bacteria, viruses, or other dangerous biological agents, particularly those found in genetic recombination studies or in clinical microbiology labs.
250. biohydrology
Definition:
The study of the interactions between the water cycle and plants and animals.
251. bioimplant
Definition:
An implanted prothesis made of biosynthetic material.
252. bioinformatics
Definition:
The use of computers in solving information problems in the life sciences; mainly, it involves the creation of extensive electronic databases on genomes, protein sequences, etc. Secondarily, it involves techniques such as the three-dimensional modeling of biomolecules and biologic systems.
253. bioinstrumentation
Definition:
The use of machines and sensors to monitor physiological data from the body.
254. bioleaching
Definition:
255. biolistic
Author: ForBio Ltd.
Definition:
Referring to methods which employ particle bombardment to introduce DNA into cells or protoplasts.
256. biolistic gun
Author: ForBio Ltd.
Definition:
A mechanical device for introducing foreign genes into plants by physical injection.
257. biological agent
Definition:
A disease-causing microorganism or virus, or other toxic biological matter, which is used as a weapon during war.
258. biological clock
Definition:
An internal biological mechanism which controls certain biological rhythms and biocycles, such as metabolism, sleep cycles, photosynthesis.
259. biological control (biocontrol)
Definition:
The agricultural use of living things, such as parasites, diseases, and predators, to control or eliminate others, such as weeds and pests, rather than by using chemicals (herbicides and pesticides).
260. biological engineering
Definition:
A type of artificial selection; the creation of plant or animal breeds that are agriculturally or industrially useful. Compare natural selection.
261. biological half-life
Definition:
The amount of time it takes the body to eliminate half of the amount of a chemical after it has been absorbed by the body.
262. biological half-life (t 1/2)
Definition:
This is the time required for one-half of the total amount of a particular substance in a biological system to be consumed or broken down by biological processes when the rate of removal is approximately exponential. Toxic chemicals with a long biological half-life (such as some pesticides) will tend to accumulate in the body and are, therefore, more likely to be harmful. A substance with a short biological half-life may still accumulate if a portion of it it becomes tightly bound to bone or other tissues, even if most of it is quickly cleared from the body.
263. biological magnification (biomagnification)
Definition:
The process by which toxins such as pesticides build up in each successive link in the food chain; for instance, a given population of beetles may have very low levels of a fat-soluble pesticide, but the pesticide will build to much greater levels in the fat of a bird that eats those beetles, and the pesticide will reach greater levels still in a human or panther that eats the beetle-eating birds.
264. biological monitoring
Definition:
This is the periodic examination of biological specimens for the purposes of monitoring their exposure to or the effects of potentially toxic chemicals to the environment. This is normally done by analyzing the amounts of the toxic substances or their metabolites present in body tissues and fluids. The term is also used to mean assessment of the biological status of populations and communities of organisms at risk, in order to protect them and to gain an early warning of possible hazards to human health.
265. biological oceanography
Definition:
The study of marine plants and animals and the way they interact with the marine environments. Similar to the study of marine biology.
266. biological response modifier
Definition:
One of a group of proteins which modify the immune response of an organism.
267. biological response modifiers
Definition:
Natural or artificial substances that enhance or restore normal immune defenses.
268. biological specificity
Definition:
The specific, orderly patterns of development and metabolism which define and characterize an individual and its species.
269. biological value (BV)
Definition:
The nutritional value of a protein, usually measured in comparison to the nutritional value of egg protein, which is the highest possible (BV=0.9 - 1.00).
270. biological warfare
Definition:
The military use of harmful biological agents such as pathogenic bacteria.
271. biologics
Author: Susan
A.Hagedorn
Definition:
Agents, such as vaccines, that give immunity to diseases or harmful biotic stresses.
272. biology
Definition:
The scientific study of living organisms.
273. bioluminescence
Definition:
The production of electricity within the body which can be seen as visible light. Some organisms which have this ability are glowworms, fireflies, some jellyfish, some fungi, and some deep-sea fish.
274. biolysis
Definition:
The decay or decomposition of organic matter into simpler chemicals by organisms.
275. biomarker
Definition:
A pharmacological or physiological measurement which is used to predict a toxic event in an animal.
276. biomarker
Definition:
A specific biochemical in the body which has a particular molecular feature that makes it useful for measuring the progress of disease or the effects of treatment.
277. biomass
Definition:
278. biomaterial
Definition:
Any nondrug material that can be used to treat, enhance, or replace any tissue, organ, or function in an organism.
279. biome
Definition:
A region which has distinct types of organisms, substrates, and climate, all interacting to produce a large, distinct, and complex biotic community.
280. biomechanical engineering
Definition:
This is the use of engineering/mechanical principles to solve problems in biology and medicine.
281. biomechanics
Definition:
The study of the body in terms of its mechanical structure and properties. Locomotion of the body is one of the more important things to which the mechanical laws are applied for study.
282. biomechanics
Definition:
This is the study of how living organisms move, grow, etc. in relation to mechanical principles.
283. biomedical engineering
Definition:
The use of engineering technology, instrumentation and methods to solve medical problems, such as improving our understanding of physiology and the manufacture of artificial limbs and organs.
284. biomedicine
Definition:
A general term which means research done in the fields of biology, biochemistry, and chemistry for application in medicine.
285. biometer
Definition:
A device which is used to measure the tiny amounts of carbon dioxide that functioning tissues give off.
286. biometrical genetics
Definition:
The mathematical approach to the study of the inheritance of different phenotypes, or physical characteristics, as a result of plant or animal breeding.
287. biometrics (biometry)
Definition:
288. biomicroscopy
Definition:
The examination of tissues on a microscopic level. Could refer to the specific examination of the cornea or lens of the eye, using a corneal microscope and a slit lamp.
289. biomimetics
Definition:
A branch of biology that uses biological systems as a model to develop synthetic systems.
290. biomolecule
Definition:
Any organic molecule that is an essential part of a living organism.
291. bionavigation
Definition:
The ability of certain animals to navigate by instinct to specific sites, apparently without using any landmarks. Examples are salmon returning to the same rivers where they were born, birds returning to the same nesting sites after annual migrations, or Florida green tortoises finding the same beaches upon which to lay their eggs.
292. bionics
Definition:
The study of the structure and function of organisms in order to apply this knowledge to the creation or modification of mechanical or electronic devices.
293. bionucleonics
Definition:
The study of how radioactive materials or rare stable chemical isotopes can be applied to biologic systems.
294. biopack (biopak)
Definition:
A container for living organisms used during biological experiments done in space; this container monitors the organisms' biological functions.
295. biophagous
Definition:
To feed on live things.
296. biophile
Definition:
A chemical element which occurs naturally in living organisms or organic matter, such as carbon, hydrogen, oxygen, and nitrogen.
297. biophysics
Definition:
The scientific study of the physics of organisms and biological structure and processes.
298. biophysiologist
Definition:
A biophysiologist is a scientist who studies how non-human organisms function.
299. biophysiology
Definition:
Biophysiology is the scientific study of how non-human organisms function.
300. bioplast
Definition:
A mass of live protoplasm which is functionally independent of other living things. An amebic cell.
301. biopolymer
Definition:
Any macromolecule which can be found within a living thing, such as proteins (essentially long chains of amino acids), nucleic acids (such as DNA or RNA), and polysaccharides (long chains of simple sugars).
302. biopotency
Definition:
The strength of a chemical substance on the body; how well or how far it can act on a biological system.
303. biopotential
Definition:
The amount of energy in biologic matter available to transform into kinetic energy (the type of energy which is seen during activity), before this energy is actually manifested by an organism.
304. bioprocess
Definition:
The process of preparing a biological product (especially one involving genetic engineering) for commercial use.
305. biopsy
Definition:
306. biopterin
Image:
View the chemical structure
Definition:
An enzymatic cofactor which is involved in some oxidation-reduction reactions; it is derived from the protein pterin.
307. bioreactor
Definition:
A closed container used for enzyme reactions and fermentation.
308. bioremediation
Author: Susan
A.Hagedorn
Definition:
The use of plants or microorganisms to clean up pollution or to solve other environmental problems.
309. biosafety
Definition:
A series of procedures in the laboratory to ensure that pathogenic microbes are safely contained.
310. biosatellite
Definition:
A space satellite that can support life forms.
311. biosensor
Definition:
312. bioseries
Definition:
A series of recognizable evolutionary changes in a single inheritable characteristic.
313. biosphere
Definition:
The sum of all the organisms living on or in this planet.
314. biostabilizer
Definition:
A type of composting system which involves tumbling moist soil waste in a drum until the material becomes a fine-grained, dark compost.
315. biostasis
Definition:
The ability of an organism to tolerate changes in its environment without having to adapt to them.
316. biostat
Definition:
A container in which the organisms in a medium (such as lake water) are monitored and measured.
317. biostatistics
Definition:
The use of statistics to analyze biological data.
318. biosurfactant
Definition:
A chemical produced by a living organism that decreases the surface tension of water.
319. biosynthesis
Definition:
The creation of molecules in living organisms.
320. biota
Definition:
321. biotechnical
Definition:
Having to do with biotechnology, or applying its techniques and principles.
322. biotechnical engineering
Author:
Definition:
Civil engineering methods incorporating organic materials to produce functional structures that are also aesthetically pleasing, provide wildlife habitat, and provide sites for revegetation.
323. biotechnology
Definition:
The industrial use of living organisms or biological techniques developed through basic research. Biotechnology products include antibiotics, insulin, interferon, recombinant DNA, and techniques such as waste recycling.
Much older forms of biotechnology include breadmaking, cheesemaking and brewing wine and beer.
324. biotic
Definition:
Having to do with living things. Something that is caused by, or produced by living things. Having to do with the biological aspects of an environment (as opposed to geological, etc. aspects).
325. biotic community
Definition:
326. biotic potential
Definition:
The potential growth a population of living things can expect if it were living under ideal environmental circumstances.
327. biotic stress
Author: Susan
A.Hagedorn
Definition:
328. biotin (vitamin H, coenzyme R, bioepiderm)
Image:
View the chemical structure
Definition:
A water-soluble vitamin (a member of the B complex vitamins) that is important because it replenishes an intermediate in the Krebs cycle. It is also used in biochemistry to detect certain protein and DNA interaction.
329. biotope
Definition:
330. biotoxin
Definition:
331. biotransformation (bioconversion)
Definition:
332. biotron
Definition:
A chamber used for biological experiments. In it, environmental conditions can be completely controlled, thus allowing researchers to test the effects of environmental changes on organisms.
333. biotroph
Definition:
An organism which cannot survive or reproduce unless it is on another organism. For example, fleas.
334. biotype (adj. biotypic)
Definition:
335. bioultrasonics
Definition:
The use of ultrasonic sound for medical treatment or other biological purposes.
336. Biozzi mice
Definition:
Any genetic line of mice which has been bred to have unusually high or unusually low antibody responses to various antigens.
337. biparietal diameter (BPD)
Author: Guo Li
Definition:
One of the ultrasound measurements of the human fetus (others are head circumference, abdominal circumference, and femur length) which correlates with the gestational age.
338. bipartite
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Divided, nearly to the base, into two parts. Compare bifid.
339. biphasic growth curve
Definition:
A particular type of growth curve seen in cultured microorganisms in which they have two exponential growth stages separated by a plateau phase. This double-hump curve is produced when the microbes are cultured using two carbon sources, one of which must be used up before the second can be used.
340. biphasic insulin
Author: PharmInfoNet
Definition:
A type of insulin that is a mixture of intermediate- and fast-acting insulin.
341. bipinnate
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Of leaves, twice pinnately divided. Compare pinnate, tripinnate.
342. birth control (contraception, family planning)
Definition:
In general, birth control or contraception is anything that prevents a woman from becoming pregnant.
The most basic and cheapest form of contraception is abstinence (not engaging in sexual intercourse at all). However, abstaining from sex can cause great stress and frustration in some, since the human sex drive can be quite powerful.
A variation on abstinence is fertility awareness (also known as "natural family planning"). This method involves a couple avoiding intercourse during the times that the woman is most likely to be fertile. This method requires that the woman be very aware of her own body and her reproductive cycle; some estimate that this method has a 70%-98% rate of success, depending on the regularity of the woman's cycle and the specific monitoring technique used. Signs that a woman has ovulated (and is therefore fertile) include a sudden change in basal body temperature, changes in vaginal mucus, or a combination of the two. A woman is least likely to be fertile during her menstrual period and for a few days thereafter.
Barrier methods of birth control work by preventing sperm from reaching the egg. Barrier methods work best in conjunction with spermicides (creams or jellies that contain chemicals that kill sperm and sometimes disease-causing microorganisms). Because barrier methods also prevent the exchange of body fluids to varying degrees, they are also useful in preventing the transmission of venereal diseases. Barrier methods include:
Other birth control methods work by altering a woman's hormones so as to render her infertile (male hormonal birth control is being researched). Hormonal methods include:
Other women may use intrauterine devices (IUDs), which work mainly by preventing the fertilized egg from implanting in the wall of the uterus. Other women use abortion (surgery to remove or drugs to induce the expulsion of an embryo or fetus) as a last-ditch effort at birth control.
If a couple wants no children at all, they may undergo surgery to render themselves sterile. In women, this procedure is generally a tubal ligation (cutting or blocking the Fallopian tubes, which carry the eggs from the ovaries). In males it is a vasectomy (cutting or blocking the tubes that carry sperm from the testis). These procedures can sometimes be reversed.
343. bis
Definition:
This Latin term, which is frequently used in medicine, means "twice".
344. bis in die (b.i.d.)
Definition:
This Latin term, which is frequently used in medicine, means "twice daily".
345. biseriate
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
Arranged in two rows or whorls.
346. Bisphospoglycerate (1,3-Bisphosphoglycerate; 1,3BPG)
Image: View
the Chemical Structure
Definition:
Previously known as 1,3-diphosphoglycerate (1,3DPG), this molecule is the first molecule that generates ATP in glycolysis. Its phosphoryl group generates a high-potential phosphorylated compound through a redox reaction.
1,3BPG is also responsible for the production of an allosteric effector of hemoglobin, 2,3-bisphosphoglycerate (2,3BPG). In this reaction, a phosphoryl group is transferred from 1,3BPG to the C-2 of 3PG. This yields 2,3BPG and a different 3PG molecule.
347. bithorax (bithorax complex)
Definition:
A group of genes (at least nine) found in the fruit fly genus Drosophila which codes for proper segmenting of the thorax (the middle body part of an insect, between the head and the abdomen) during the fruit fly's early development.
348. bivalent (tetrad)
Definition:
A pair of homologous chromosomes which have joined together (are synapsed) during prophase I and metaphase I of meiosis.
349. black smoker
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
An undersea thermal vent emitting very hot (270-380 degrees C) water and minerals.
350. blade
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
The expanded part of a leaf or petal.
351. blastocoel
Definition:
The fluid-filled cavity in the middle of a blastula, an early stage in the development of the embryo.
352. blastocyst (blastodermic vesicle)
Definition:
A stage in the development of a mammalian embryo just after the blastula stage, where the hollow ball of cells becomes two layers of cells - one layer, called the trophoblast, is at one end of the embryo and attaches it to the wall of the uterus so that it can receive nutrition during its development. The other is a single-cell layer which surrounds the blastocoele, the fluid-filled hollow part of the ball.
353. blastomere
Definition:
One of the cells of the early embryo, formed during the first few divisions of the newly-fertilized zygote.
354. blastomycosis
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
An acute or chronic mycosis which usually affects man and animals (e.g. dogs). Blastomycosis is caused by a fungus called Blastomyces dermatitidis and occurs in North America, Africa and Israel. Infection apparently occurs by inhalation of spores from the fungus although B. dermatitidis has proved difficult to isolate from environmental habitats.
355. blastula
Definition:
A hollow ball of cells formed at the end of the cleavage stage of embryonic development.
356. bleeding time
Author: Guo Li
Definition:
This is the time for the bleeding to stop from an artificially made superficial incision on the forearm. The mechanism to stop bleeding involves vascular contraction, platelet function, and the participation of the non-clotting portion of the Factor VIII. Bleeding time may be normal in disorders of the coagulation system. Normal range is 1 to 8 minutes.
Bleeding time is elevated in the following conditions:
357. bleomycin
Definition:
An antibiotic which came from the bacteria Streptomyces verticellus and is used to treat a variety of cancers, including Hodgkin's disease and cancers of the testicles.
358. bloating
Author: Guo Li
Definition:
Bloating is the sensation of excessive fullness of the stomach/abdomen.
359. blood agar
Definition:
An agar-based medium which has been enriched with sterilized, defibinated blood (sheep, rabbit or horse). It is used for primary plating and subculturing, especially to determine bacterial hemolysis.
360. blood clot
Definition:
A mass of coagulated/solidified blood.
361. blood clotting factor
Definition:
Any of a number of different protein factors which, when acting together, can form a blood clot shortly after platelets have broken at the site of the wound. The factors have Roman numeral names, like VII, VIII, IX, X, XI, and XIII. Defects in the genes which code for any of these factors result in genetic diseases like hemophilia, which results from a defect in the gene for factor VIII or IX.
362. blood count
Definition:
A numerical representation of the number of formed elements, such as red blood cells or platelets, found in a cubic millimeter of blood. The number is obtained by counting the cells in an accurate volume of diluted blood.
363. blood culture
Definition:
A preparation of blood, which is used either for general analysis or to grow specific blood elements (such as white blood cells).
364. blood glucose
Author: PharmInfoNet
Definition:
The main sugar that the body makes from the three elements of food--proteins, fats, and carbohydrates--but mostly from carbohydrates. Glucose is the major source of energy for living cells and is carried to each cell through the bloodstream. However, the cells cannot use glucose without the help of insulin.
365. blood glucose meter
Author: PharmInfoNet
Definition:
A machine that helps test how much glucose (sugar) is in the blood. A specially coated strip containing a fresh sample of blood is inserted in a machine, when then calculates the correct level of glucose in the blood sample and shows the result in a digital display. Some meters have a memory that can store results from multiple tests.
366. blood glucose monitoring
Author: PharmInfoNet
Definition:
A way of testing how much glucose (sugar) is in the blood. A drop of blood, usually taken from the fingertip, is placed on the end of a specially coated strip, called a testing strip. The strip has a chemical on it that makes it change color according to how much glucose is in the blood. A person can tell if the level of glucose is low, high, or normal in one of two ways. The first is by comparing the color on the end of the strip to a color chart that is printed on the side of the test strip container. The second is by inserting the strip into a small machine, called a meter, which "reads" the strip and shows the level of blood glucose in a digital window display. Blood testing is more accurate than urine testing in monitoring blood glucose levels because it shows what the current level of glucose is, rather than what the level was an hour or so previously.
367. blood plasma
Author: Guo Li
Definition:
This is whole blood minus the cells.
368. blood pressure
Author: Guo Li
Definition:
The pressure of blood in a blood vessel:
369. blood pressure (systolic blood pressure, diastolic blood pressure)
Author: PharmInfoNet
Definition:
The force of the blood on the walls of arteries. Two levels of blood pressure are measured-the higher, or systolic, pressure, which occurs each time the heart pushes blood into the vessels, and the lower, or diastolic, pressure, which occurs when the heart rests. In a blood pressure reading of 120/80, for example, 120 is the systolic pressure and 80 is the diastolic pressure. A reading of 120/80 is said to be the normal range. Blood pressure that is too high can cause health problems such as heart attacks and strokes.
370. blood serum
Author: Guo Li
Definition:
This is blood plasma minus the clots.
371. blood smear
Author: Guo Li
Definition:
This is the microscopic examination of anticoagulated blood obtained from vein pucture. The characteristics of red cells, white cells, and platelets are observed for their sizes, shapes, numbers, color, morphologies, and the way their group together. Certain presentation of blood smear may suggest disease conditions.
372. blood urea nitrogen (BUN)
Author: PharmInfoNet
Definition:
A waste product of the kidneys. Increased levels of BUN in the blood may indicate early kidney damage.
373. blood urea nitrogen (BUN)
Author: Guo Li
Definition:
This is an indicator of glomerular filtration rate. However, because it is dependent upon the protein intake in the diet and renal function, it is an insensitive indicator. At least 50 % of the kidney substance must be destroyed before BUN is elevated.
Normal range: 3 - 7 mmol/L
374. blood vessel
Author: PharmInfoNet
Definition:
Tubes that act like a system of roads or canals to carry blood to and from all parts of the body. The three main types of blood vessels are arteries, veins, and capillaries. The heart pumps blood through these vessels so that the blood can carry with it oxygen and nutrients that the cells need or take away waste that the cells do not need.
375. blood-brain barrier
Definition:
A barrier made up of neuroglia and capillary walls which limits the movement of substances in the bloodstream into the brain.
376. blood-testis barrier
Author: Fertilitext
Definition:
377. bloom
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
A blossom; the flower of a plant; an expanded bud; the opening of flowers in general, leaves, flowers, or fruits.
378. blossom
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
A flower or bloom, esp. of a fruit bearing plant. A state or time of flowering, literally, and figuratively.
379. blunt-end DNA
Definition:
A fragment of a DNA molecule in which the ends of both strands are even with each other rather than one strand being longer than the other.
380. blunt-end ligation
Definition:
A lab technique to join together two pieces of blunt-end DNA, such as an insert into a cloning vector, which requires the enzyme ligase because there are no single-stranded overhanging ends for the attachment to form more spontaneously, by itself.
381. bobbed
Definition:
The name for a variety of Drosophila (a fruit fly) mutation where the bristles (mostly on the back of the head) are very short and thin compared to normal fruit fly bristles. Also, the number of copies of genes encoding rRNA molecules are reduced.The mutant allele is located on the sex chromosomes and is recessive.
382. body temperature
Author: Guo Li
Definition:
Normal oral temperature is 36.3° C to 37.1° C or 97.3° to 98.8° F. The rectal temperature is about 0.5° C or 1° F higher than the oral temperature.
383. body-centered cubic (bcc)
Definition:
A molecular structure in which a cube-shaped lattice is formed with one atom in the middle and four other atoms arranged around it as the corners of the cube.
384. bog
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
A quagmire covered with grass or other plants; wet, spongy ground; a small marsh; plant community on wet, very acid peat.
385. boiling point
Definition:
This is the temperature at which the vapor pressure of a given liquid reaches atmospheric pressure (and thus starts to boil).
386. boiling point elevation
Definition:
This is the phenomenon of increasing the temperature at which a liquid boils by dissolving another substance in the liquid (for example, you can raise the temperature at which water boils by adding salt to it).
387. bole
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
The trunk of a tree, below the lowest branch. Compare canopy.
388. bolus
Definition:
389. bomb calorimeter
Definition:
An instrument which measures the heat released or absorbed during a chemical reaction.
390. bond angle
Definition:
This refers to the angle formed between two nuclei which are linked together.
391. bond dissociation energy
Definition:
This is the energy needed to break the bonds between two linked atoms.
392. bond energy
Definition:
The energy needed to break a molecular bond.
393. bond length
Definition:
This is the distance between the nuclei of two atoms which have formed bonds with each other.
394. bone marrow
Definition:
The soft inner portion of bones. Three types of blood cells are created in the bone marrow:
395. bone marrow biopsy
Author: Guo Li
Definition:
This is obtained by inserting a hollow needle into the bone cavity (usually the iliac crest or sternum). A specimen, after decalcification, sectioning, and staining, is examined under low power microscopy. The staining characteristics, number and morphology of cells may be suggestive and sometimes diagnostic of certain blood related diseases.
Material effects, risks and side effects: prolonged bleeding time if the patient has bleeding tendency, infection, the needle on the sternum may suddenly go through the bone and puncture the heart or large blood vessels.
396. bone marrow harvesting
Definition:
A medical procedure which involves collecting healthy bone marrow which will be stored and used in a future bone marrow transplant.
397. bone scan
Author: Guo Li
Definition:
This is a technique to demonstrate abnormal metabolic activity in bone. The procedure involves intravenous injection of the radionuclide which is usually sodium pertechnetate (technetium Tc99m methylene diphosphonate) which is taken up in areas of active growth in bone.
It is possible to differentiate normal growth and excessive growth from the level of radioactivity emitted. This method can detect metastatic tumor to bone from the prostate, breast, lung, kidney, bladder and thyroid, arthritis, osteomyelitis, and new fractures. Other methods include WBC scan and gallium scan.
398. boom
Author:
Definition:
A floating log or similar element designed to dampen surface waves or control the movement of drift.
399. Born-Haber cycle
Definition:
This is a mathematical description of the relationship between the electron affinity, heats of atomization, ionization energy and lattice energy of ionic compounds.
400. borrow pits
Author:
Definition:
Excavations created by the surface mining of rock, unconsolidated geologic deposits or soil to provide material (borrow) for fill elsewhere.
401. botanist
Definition:
A botanist is a scientist who studies plants.
402. botany
Definition:
The scientific study of plant life.
403. bottleneck effect
Definition:
This is a type of genetic drift caused by the rapid decrease in a population's size due to a natural disaster (fire, flood, etc.) that results in a new mating population that is not genetically representative of the original group.
404. bottomland
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
Lowlands along streams and rivers, usually on alluvial floodplains, that are periodically flooded.
405. botulin (botulinus toxin, botulismotoxin)
Definition:
A very strong poison which affects the nervous system, made by the bacteria Clostridium botulinum. The poison causes the food poisoning known as botulism.
406. botulism (botulism disease)
Definition:
A type of food poisoning caused by the toxin botulin, which is made by the bacteria Clostridium botulinum. Symptoms of the disease include vomiting, stomach trouble and indigestion, abdominal pain, trouble seeing, and a barking cough.
407. boulders
Author:
Definition:
408. bovine
Definition:
Relating to, affecting, resembling or derived from a cow or bull.
409. bovine somatotropin (bovine growth hormone, bST, BGH)
Definition:
A growth hormone found in cattle; a version of this hormone is also found in all mammals, including humans. Injections of this hormone dramatically increase the milk production of lactating cows. In past years, the hormone was very expensive because it could only be taken from slaughtered cows, but in the early '90s researchers learned how to genetically engineered the bacterium E. coli to produce it. Now, many dairy producers use the hormone, but the practice is controversial because the use of bST may increase the incidence of mastitis (udder infection) in cows, and the long-term human health effects of the slightly increased hormone levels in the milk from treated cows have not been established. See also porcine somatotrophin.
410. bovine spongiform encephalitis (BSE, bovine spongiform
encephalopathy)
Definition:
A neuro-degenerative disease found in domestic cattle which is related to a number of other similar diseases found in other animal species, including humans. The most well-known of these other diseases are scrapie, found in sheep, and Creutzfeldt-Jakob Disease, found in humans. The family of diseases is caused by an abnormally-configured protein called a prion. The function of the protein in its normal configuration is not certain. The diseases are similar to Alzheimer's disease in humans, except the progressive loss of brain function is more rapid.
411. Boyle's Law
Definition:
This law states that the volume of a sample of gas is, at a constant temperature, inversely proportional to the pressure of that gas.
412. brachiopod (Brachiopoda)
Definition:
A phylum of invertebrate animals often grouped with two other phyla under the name "Lophophorates." General characteristics include: a pair of protective shells (giving them a superficial resemblance to the bivalves - i.e. clams), a stalk protruding from the rear called a "pedicle" which anchors the animal to the sea floor, and a lophophore (a ridge with many tiny tentacles on it, used to catch food particles floating by). Brachiopod shells come in many different shapes and sizes. Brachiopods were extremely abundant during the Paleozoic era (both in terms of numbers of individuals and numbers of species), but were practically wiped out around 300 million years ago during the Permian mass extinction.
Compare gastropod
413. brachyblast
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A short branch; a spur shoot.
414. brackish
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
Mixed with salt; briny.
415. bract
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A leaf-like structure, different in form from the foliage leaves and without an axillary bud, associated with an inflorescence or flower.
416. bracteolate
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
Furnished with bracteoles.
417. bracteole
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
418. bradycardia
Definition:
Bradycardia is an abnormally slow heart rate. In healthy adults, the normal resting heart rate is about 70-80 beats per minute (athletes often have resting heart rates in the 60s and sometimes lower). In newborn babies, the normal heart rate is 120-160 beats per minute.
419. bradykinin (kallidin I, callideic I)
Definition:
420. braided stream
Author:
Definition:
Stream that forms an interlacing network of branching and recombining channels separated by branch islands or channel bars. (See also channel braiding.)
421. braiding of stream channels
Author:
Definition:
Successive division and rejoining of streamflow with accompanying islands. (A braided stream is composed of anabranches.)
422. brain (encephalon)
Definition:
The center of the central nervous system; a mass of nerve tissue in the cranium that receives and transmits neural impulses and controls and directs an organism's behavior and actions.
423. brain death
Author: Guo Li
Definition:
A definition of death based on the absolute and total loss of the individual's brain function that is irreversible.
This definition of death is a medical definition which may differ from religious, ethical, philosophical or cultural definitions of death.
Modern anesthesia techniques can render a person without brain activities (flat EEG), totally paralyzed (with neuromuscular blocking agents), and with no cardiac (heart) activity (with cardioplegic solutions), such as is the case when a patient is undergoing extracorporeal circulation during cardiac anesthesia. In this case, despite that the patient physically resembles that of a dead person, the condition is reversible.
Therefore, to declare brain death, one must follow a protocol of clinical testing as well as preclude anesthetic causes and hypothermia.
424. brain scan
Author: Guo Li
Definition:
This is a technique to demonstrate the pattern of blood perfusion of the brain. The procedure involves intravenous injection of the radionuclide such as technetium 99m pertechnetate, mercury-210, or radioiodinated albumin. This method can diagnose cerebral hemorrhage, cerebrovascular accidents (CVA), tumor, hematoma, AV malformations, and aneurysms.
425. brain stem (brainstem)
Definition:
The lowest part of the brain, which merges with the spinal cord. It consists of the medulla oblongata, midbrain and pons.
426. branch
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
A natural division of a plant stem.
427. branch migration
Definition:
Movement of the branch point in a branched DNA sequence formed from two parent DNA molecules with practically identical sequences. See Holliday intermediate.
428. branchlet
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
A small, usually terminal branch.
429. Brassica (Brassicaceae, Cruciferae)
Definition:
A genus of plants belonging to the mustard family Brassicaceae. The whole family includes a total of 376 different genera and 3,200 different species. The family is also known as "Cruciferae" because the four petaled flowers of these plants look like crosses. The plants are distributed worldwide and have annual (living one year), biennial (living two years) and perennial (living many years) members.
Member species of genus Brassica include Brassica napus which produces rapeseed or canola oil; Brassica nigra which produces yellow mustard; Brassica oleracea whose subspecies and strains include kale and collard greens (B. oleracea acephala), broccoli (B. oleracea botrytis), cauliflower (B. oleracea cauliflora), head cabbage (B. oleracea capitata), brussel sprouts (B. oleracea gemmifera), and kohlrabi (B. oleracea gongycoides); and Brassica rapa, whose subspecies include pak choi (B. rapa chinensis), Chinese cabbage (B. rapa pekinensis), and turnip (B. rapa rapifera). Also, one subspecies of B. rapa is used as a model organism to study genetics, molecular biology, plant breeding, cell biology, and physiology; it is called the "rapid cycling" Brassica or RCBr or the Wisconsin Fast PlantTM, and was developed specifically for scientific study. Additionally, the radish Raphanus sativus is a member of the Brassicaceae family. The full taxonomic classification is kingdom Plantae, division Tracheophyta, subdivision Spermatophyta, class Angiospermae, subclass Dicotyledeonae, order Papaverales, family Brassicaceae.
430. BRCA1
Definition:
BRCA1 is a tumor-supressing gene; if even one copy of it is damaged, cancer can develop. Certain mutations confer a high probability (85% lifetime risk) of developing breast cancer, and other types cause ovarian cancer. Familial mutations of this gene are particularly common among people in the Ashkenazi Jewish ethnic group.
431. breast ultrasound
Author: Guo Li
Definition:
Ultrasound can differentiate cysts and solid masses of the breast when x-ray examination of the breast cannot. Ultrasound is often used to localize the mass with a marker (e.g. a wire) which the surgeon uses as a guide to cut out the mass for examination.
432. breeder reactor
Definition:
This is a nuclear reactor which produces nuclear fuel as it produces energy for electricity.
433. brewing
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
The manufacture of alcoholic beverages such as beer from the fermentation of malted grains.
434. bristle
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
Stiff, strong but slender hair or trichome.
435. brittle diabetes (labile diabetes, unstable diabetes)
Author: PharmInfoNet
Definition:
A term used when a person's blood glucose (sugar) level often swings quickly from high to low and from low to high.
436. broadcast seeding
Author:
Definition:
437. Bromocryptine (Parlodel)
Author: Fertilitext
Definition:
438. bronchiectasis
Author: Guo Li
Definition:
A condition in which bronchi of the lungs are abnormally and permanently dilated usually due to weakened bronchial wall, such as after an infection.
439. bronchiolitis
Author: Guo Li
Definition:
An inflammation of the bronchioles of the lungs.
440. bronchoscopy
Author: Guo Li
Definition:
This is the procedure in which an instrument is introduced through the mouth or the nostril to examine the upper airway: nasal pharynx, oral pharynx, larynx, trachea and the bronchi. Biopsy and cell samples (sputum or bronchial washings) could be obtained and foreign body could be retrieved. In rigid bronchoscopy a metal tube is used. In fiberoptic bronchoscopy a flexible fiberoptic instrument is used. Laser excision of bronchial tumors is also performed through a bronchoscope.
Material effects, risks and side effects: bleeding after biopsy; coughing; laryngospasm; aspiration; collapse of small airways; hypoxemia.
441. bronze diabetes (hemochromatosis)
Definition:
A genetic disease in which the body takes in too much iron from food; this causes excess iron to be deposited in the liver and heart and other organs, eventually leading to organ failure and death. This illness is called "bronze diabetes" because the kidneys often fail, leading to symptoms similar to those found with diabetes mellitus, and because the deposition of iron into the skin makes the person look like he or she has an all-over tan.
It used to be believed that this disease was rare and mainly affected people of Caucasian descent, but in recent years scientists have realized it is more common and affects a wide range of ethnic groups. Some believe that this genetic defect actually helps people (especially women) survive in areas where malnutrition is widespread and iron is scarce in food.
Regular bloodletting (or blood donation) may help people suffering from this disease.
442. broom-like
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
In botany terminology, describes a plant which has many branches parallel or almost so and usually erect.
443. broth
Definition:
444. Brown-Séquard's syndrome
Author: Guo Li
Definition:
Brown-Séquard's syndrome is a neurological disorder in which there is a unilateral spinal cord lesion that causes:
445. browse protection
Author:
Definition:
Mechanical or chemical protection of shrubs and trees against damage caused by game and grazing animals.
446. browsed
Author:
Definition:
Any tree with several centimeters of one or more limb tips, including but not restricted to, the tallest limb, bitten off by deer or other wildlife.
447. brush habitat
Author:
Definition:
Includes a wide variety of plant and animal life dominated by and associated with coastal scrub and chaparral.
448. brush layering
Author:
Definition:
Placing horizontal layers of tree branches or twigs in a gully or along a slope and then partially covering the branches with soil; the branches act to hold the soil in place and to absorb momentum from water flowing over the area.
449. bryophyte
Definition:
Any primitive plant in the division Bryophyta; includes liverworts, mosses, and hornworts.
450. bubbler irrigation
Author:
Definition:
An irrigation system which injects a slow trickle of water into the ground next to plant roots.
451. buckminsterfullerene (buckyball, C60)
Definition:
A hollow, spherical molecule consisting of 60 carbon atoms arranged in a soccer ball pattern of hexagons and pentagons. The molecule can superconduct, lubricate, and absorb light. The molecule is a type of fullerene, was the first one to be discovered and studied, and is named after the architect R. Buckminster Fuller.
452. bud
Author: Mirrored from
Dave Sutton's Aquatic Plant
Glossary
Definition:
A small swelling or projection on a plant, from which a shoot, cluster of leaves, or flowers develops; a rudimentary, undeveloped shoot, leaf, or flower.
453. Budd-Chiari syndrome (Chiari's syndrome, Chiari-Budd syndrome)
Author: Guo Li
Definition:
Budd-Chiari syndrome is characterized by a enlarged, tender liver with intractable ascites. This syndrome is often caused by the thrombosis or obstruction of the hepatic vein. Pathological finding may reveal thickening of the intima of the hepatic veins.
454. budding
Author: Mirrored from
Tsute Chen's
Glossary of Microbiology
Definition:
455. buffer
Definition:
A chemical used to maintain the pH of a solution by absorbing hydrogen ions (which would make it more acidic) or hydroxyl ions (which would make it more basic).
456. buffer capacity
Definition:
The ability of a buffer solution to absorb added alkali or acid while maintaining the solution's pH.
457. buffer strip (leave strip)
Author:
Definition:
Strip of vegetation left intact along a stream or lake during and after logging.
458. buffer zone
Author:
Definition:
An area of land separating two distinct land uses that acts to soften or mitigate the effects of one land use on the other.
459. bulb
Definition:
A modified underground stem which has one or more buds enclosed in fleshy modified leaves or scales which supply energy to the bud(s) when they start to grow; onions and tulips have bulbs.
460. bulbel (bulblet)
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A bulb arising from another bulb.
461. bulbil
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A small, deciduous bulb (or tuber) formed in the axil of a leaf and functioning to propagate the plant vegetatively.
462. bulked segregant analysis
Author: ForBio Ltd.
Definition:
Marker analysis applied to two bulked DNA samples prepared from individuals selected, in a segregating population, to be contrasting with respect to a trait of interest.
463. bulla
Author: Guo Li
Definition:
A fluid-filled skin lesion that is greater than 1.0 cm in diameter and usually elevated above the surrounding skin.
464. bunch grass
Author:
Definition:
Any of a number of perennial grasses (family Gramineae) which grow in tight clumps and regenerate each year from deep roots.
465. Bunsen burner
Definition:
A small, widely-used piece of laboratory equipment which produces an adjustable gas flame for the purposes of heating chemical reactions and the short-term sterilization of other small pieces of laboratory equipment.
466. Bunyaviridae
Definition:
A large family of viruses containing single-stranded RNA that infect a wide range of vertebrate hosts; some are responsible for hemorrhagic fever.
467. buried soils
Author:
Definition:
468. Burkitt's lymphoma (B cell lymphoma)
Definition:
A type of cancer associated with the Epstein-Barr virus (EBV), though it is not known if EBV actually causes the tumor or not. This lymphoma of the B lymphocytes is rare in developed countries but is relatively common among people living in New Guinea and East Africa.
469. burns
Author: Guo Li
Definition:
Damage to skin or other tissues caused by agents such as fire, radiation,
or corrosive chemicals. The severity of burns:
The area of the body burned is usually expressed in percentages of the
total body surface area that has sustained second and third degree burn. The
following method can give a rough estimate of the area burn:
470. burr
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
471. Bursa of Fabricius
Definition:
A saclike organ found in the cloaca (excretory and reproductive opening) of birds which produces B lymphocytes.
472. burst number
Definition:
The number of viral particles that emerge from a cell after a viral infection has burst it open.
473. buspirone (BuSpar)
Definition:
This is a psychotropic drug with anxiolytic properties which belongs chemically to the class of compounds known as the azaspirodecanediones. It is used to treat anxiety.
474. buttress
Author: Mirrored from
Jim Croft's Flora of
Australia
Definition:
A flange of tissue protruding from the main outline of the base of a tree.
475. by-product
Definition:
A product of a chemical reaction or industrial process which is different from the desired product(s).
END
