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A
- ABC model of the control of flowering
- ABC transporter
- ABL gene
- ABO blood groups
- ABP1 (Auxin-binding protein 1)
- Abscisic acid (ABA)
- Abscission
- Absorption spectrum
- Abyssal plain
- ACE inhibitors
- Acetylcholine
- [at neuromuscular junction]
- Acetyl-CoA
- Acid
- Acid rain
- Acorn worms
- Acrosome
- ACTH (adrenocorticotropic hormone; aka corticotropin)
- Actin filaments
- [Discussion] [in cytokinesis] [in skeletal muscle]
- Actinomycetes
- Action potential
- [in muscle fiber]
- Action spectrum
- Active transport
- Activins
- [in embryonic development] [sex hormones]
- Acute lymphoblastic leukemia (ALL)
- Adaptation
- [of sense receptors] [evolutionary]
- Adaptive radiation
- Addison's disease
- Adenine
- Adeno-associated virus (AAV).
- as vector for somatic gene therapy
- Adenomatous Polyposis Coli (APC) gene
- Adenosine deaminase (ADA)
- and severe combined immunodeficiency (SCID)
- Adenosine triphosphate (ATP)
- Adenoviruses
- Adenylyl cyclase
- [and odorant receptors]
- ADH, the antidiuretic hormone (also known as vasopressin)
- Adherens junctions
- Adhesion
- Force of attraction between unlike molecules.
- Adipose tissue (fat)
- [secretion of leptin by]
- Adjuvant
- Adrenal glands, hormones of
- Adrenaline
- Adrenocorticotropic hormone (ACTH, aka corticotropin)
- Advanced waste treatment
- Adventitious root
- Aequorin
- Aerobic
- Requiring the presence of free oxygen.
- Affinity
- Strength of binding by noncovalent interactions between one site on a molecule and a monovalent ligand. [antibody affinity] [affinity maturation]
- Afrotheria
- AGAMOUS (AG)
- Agent Orange
- Aging
- Agnatha
- Agonist
- Drug that mimics the action of another. [Example]
- Agrobacterium tumefaciens
- AID (Activation-Induced cytidine Deaminase)
- AIDS (Acquired Immune Deficiency Syndrome)
- Air
- [composition of] [pollution]
- AIRE (autoimmune regulator gene)
- Alanine
- Alcohols
- Aldehydes
- Aldosterone
- Algae
- [Brown] [Green] [Golden] [Red] [culture medium for]
- Alkylation
- Addition of a carbon-containing group, such as a methyl or ethyl group, to another molecule.
- Allantois
- Allele
- Alternative version of a gene. [in Mendel's peas] [in a three-point cross] [RFLPs] [hemoglobin beta chain] [and protein polymorphisms]
- Allergen
- An antigen that provokes an allergic response.
- Allergy
- Allograft
- Allopatric speciation
- Allosteric
- Refers to a change in the properties (usually including shape) of a protein following the binding of another molecule to the protein. [Example]
- Allozyme
- Alpha1-Antitrypsin
- [deficiency ] [synthesis by transgenic sheep] [and emphysema]
- Alpha helix
- Alpha motor neurons
- Alport's syndrome
- Alternation of generations
- [Discussion] [in ferns] [in mosses]
- Alternative splicing
- Alu element
- Aluminum
- Alvarez, L.
- Alveolates
- Alveoli
- Alzheimer's disease
- Ames Test
- Amfor gene
- Amides
- Amines
- Amino acids
- Aminoglycosides
- Aminopeptidase
- Amino terminal
- Ammonia
- [in nitrogen cycle] [in urea cycle]
- Amniocentesis
- Amnion
- [in humans]
- Amniota
- AMPA receptors
- Amphetamines
- Amphibians
- Amphineura
- Amphioxus
- Amphiphilic
- Used to describe molecules containing both polar (hydrophilic) and apolar (hydrophobic) groups. Sodium stearate (a soap) is amphiphilic.
- Amygdala
- Amylase
- [pancreatic amylase]
- Amylin
- Amyloid
- Amylopectin
- Amylose
- Anabolic steroid
- Anabolism
- Anaerobic
- Not requiring the presence of free oxygen.
- Analgesics
- Analogous
- Of structures (e.g., molecules, organs) in different species having similar function(s) but inherited from different precursors.
- Anammox (anaerobic ammonia oxidation)
- Anaphase
- [in mitosis] [in meiosis]
- Anaphase-Promoting Complex/Cyclosome (APC/C)
- Anaphylaxis
- [local] [systemic]
- Androgen
- Anemia
- [immune hemolytic] [pernicious] [sickle-cell]
- Anesthetic
- Aneuploid
- Having one or more extra (or fewer) chromosomes than the normal diploid (2n) set (e.g., 2n+1, 2n-1). [trisomy 21] [X chromosomes]
- Angelman syndrome
- Angiogenesis
- Angiosperms
- [life cycle] [evolutionary relationships]
- Angiotensin
- Angiotensin converting enzyme (ACE)
- Angstrom (Å)
- Animal
- [cells] [invertebrate] [tissues] [vertebrate]
- Aniridia gene
- Annelida
- ANP (atrial natriuretic peptide)
- Antennapedia (Antp)
- [encoded homeodomain]
- Antenna pigments
- Anther
- Antheridia
- [in ferns] [in mosses]
- Anthozoa
- Anthrax
- [how its toxin works]
- Antibiotics
- Antibody
-
- [structures] [classes] [how their diversity is created] [affinity] [binding to antigen] [bispecific] [monoclonal] [specificity]
- Anticodon
- Antidepressant drugs
- Antidiuretic hormone (ADH)
- Antigen
- Antigenic determinant
- A part of an antigen to which the antibody binds. Also called an epitope. [View]
- Antigenic drift of influenza viruses
- Antigen presentation
- Antigen-Presenting Cells (APCs)
- Antigen receptors on B and T cells
- how their diversity is created
- Antimicrobial peptides
- Antioxidants
- Antiport pump.
- Antisense strand
- The strand of DNA used as the template for synthesizing RNA. (Sometimes called the Watson strand.)
[View] [Antisense oligonucleotides] [Antisense RNA]
- Antiserum
- Serum containing induced antibodies. [Example]
- Antithrombin III
- Antithymocyte globulin (ATG)
- Antitoxin
- Aorta
- APC gene
- APETALA
- Apical dominance
- Apicomplexa
- Apicoplast
- Apis mellifera, the honeybee
- [life history] [communication]
- Aplysia
- Apolipoprotein B
- [and cholesterol metabolism] [and RNA editing]
- Apomixis
- Apomorphic
- Apoplast
- Apoptosis
- Programmed cell death. [Discussion]
- Aposematic coloration
- Appetite, control of
- Aquaporin
- Aqueous humor
- Arabidopsis thaliana
- Arachidonic acid
- Arachnida
- Archaea
- Archegonia
- [in ferns] [in mosses]
- Archenteron
- ARF1 (Auxin Response Factor 1)
- Arginine
- [substrate for NO synthases]
- Arrestins
- Arteries and Arterioles
- Arteriosclerosis
- Arthropods
- Ascidians
- Ascomycetes
- Ascorbic acid (vitamin C)
- Ascus
- Asexual reproduction
- Asparagine
- Aspartic acid
- Assisted Reproductive Technology (ART)
- Association constant (K)
- Assortative mating
- Asthma
- Astrocytes
- Ataxia telangiectasia
- [ATM gene] [and aging]
- Atherosclerosis
- [and cholesterol]
- Atom
- Atomic number
- Atomic weight unit
- One-twelfth the weight of an atom of carbon-12. Also called the dalton. [More]
- Atopy
- ATP (adenosine triphosphate)
- [structure] [yield in cellular respiration]
- ATP-binding cassette
- ATP synthase
- [in photosynthesis] [in mitochondria]
- Atrial natriuretic peptide (ANP)
- Atrio-ventricular (A-V) node
- Atrium
- Australopithecus afarensis
- Autocrine
- Refers to the influence on a cell of molecules synthesized by the same cell. [More]
- Autoimmune disease
- Disease characterized by the mounting of an immune response against constituents of an individual's own tissues. Some examples: [Goodpasture's Syndrome] [Type 1 diabetes mellitus] [Immune hemolytic anemia] [Immune thrombocytopenic purpura] [Myasthenia gravis (MG)] [Multiple sclerosis (MS)] [Rheumatoid arthritis] [Systemic lupus erythematosus (SLE)] [Thyrotoxicosis (Graves' disease)]
- Autonomic nervous system
- Autophagy
- Autoradiography
- Autosome
- Any chromosome that is not a sex chromosome.
- Autotrophic
- Capable of synthesizing organic molecules from inorganic raw materials.
- Photoautotrophs use light as the source of the needed energy. Characteristic of plants, algae, and some bacteria. [Photosynthesis]
- Chemoautotrophs use the energy secured by oxidizing some inorganic substance in their surroundings. Characteristic of certain bacteria and archaeons.
- Auxin
- [actions] [and tropisms] [differential action on roots and shoots]
- Avena test
- Avery, O. T.
- Avogadro's number
- Axial element
- Axon
- [axon hillock]
- Azathioprine
- AZT
- Azidodeoxythymidine. Also called zidovudine.