Kaplan- MCAT Biology Glossary
[COMPLETE]
Exam 2023
A muscle that moves a limb away from the center of the body - Answer-Abductor
The process by which
... [Show More] substances are taken up into or across tissues - AnswerAbsorption
A NT found in NS (somatic motor neurons, preganglionic PNS/SNS nerves, and
postganglionic parasympathetic neurons); metabolized by acetylcholinesterase -
Answer-Acetylcholine
The large vesicle at *head* of a *sperm cell* containing *enzymes* that *degrade the
ovum cell membrane* to allow fertilization - Answer-Acrosome
Protein found in the cytoskeleton and muscle cells; principal constituent of the thin
filaments and *microfilaments* - Answer-Actin
An abrupt change in membrane potential of a nerve or muscle caused by changes in
membrane ionic permeability; results in conduction of an impulse in nerves or
contraction in muscles. - Answer-Action potential
An immune response (antibody production or cellular immunity) acquired in response to
exposure to an antigen. - Answer-Active immunity
Substrate-binding region of an enzyme - Answer-Active site
The development of characteristics that enable an organism to survive & reproduce in
its habitat - Answer-Adaptation
Highly specific form of immunity that retains chemical memory of each invader
encountered and is able to tailor the immune response to the specific pathogen -
Answer-Adaptive immunity
The evolutionary process by which 1 species gives rise to several species, each
specialized for different niches. - Answer-Adaptive radiation
A muscle that moves a limb toward the center of the body - Answer-Adductor
A purine base present in DNA and RNA; forms hydrogen bonds with thymine and uracil
- Answer-Adenine
A nucleotide molecule consisting of *adenosine, ribose, and 3 phosphate*; the outer 2
phosphates are bound by high-energy bonds - Answer-Adenosine triphosphate (ATP)
Refers to fatty tissues, fat-storing tissue, or fat within cells - Answer-Adipose
Refers to biological process that occurs in the presence of molecular O2 or to
organisms that can NOT live w/out oxygen - Answer-Aerobic
A neuron that picks up impulses from sensory receptors and transmits them *toward the
CNS* - Answer-Afferent (sensory) neuron
Type of *leukocyte* that does *not* contain cytoplasmic *granules*, including
lymphocytes and monocytes - Answer-Agranulocyte
Protein *synthesized in the liver* that maintains the oncotic pressure of the blood and
serves as a carrier for many drugs and hormones - Answer-Albumin
One of 4 embryonic membranes; it contains the growing embryo's waste products -
Answer-Allantois
Alternative forms of the same gene coding for a particular trait; alleles segregate during
meiosis - Answer-Allele
A type of autoimmunity in which a person's immune system becomes overactivated by
common substances in the environment - Answer-Allergy
Basic functional unit of the lung; a tiny sac specialized for passive gas exchange b/w the
lungs and the blood - Answer-Alveolus
Building blocks of proteins, each containing an amino group, a carboxylic acid group,
and a side chain (R group) attached to the alpha-carbon - Answer-Amino acids
The *innermost fluid-filled embryonic membrane*; it forms a protective sac surrounding
the embryos of birds, reptiles, and mammals - Answer-Amnion
Characteristic of a signaling cascade, in which the binding of a single peptide hormone
to a membrane-bound receptor results in a signal that increases in strength through
signaling cascade - Answer-Amplification
Refers to biological process that can occur w/out oxygen or to organism that can live
without molecular oxygen - Answer-Anaerobic
Stage of mitosis or meiosis characterized by the migration of chromatids or homologous
chromosomes to opposite poles of the dividing cell - Answer-Anaphase
Any male sex hormone, such as testosterone - Answer-Androgen
Substance that kills or inhibits the growth of bacteria or fungi (usually by disrupting cell
wall assembly or binding to ribosomes, thus inhibiting protein synthesis) - AnswerAntibiotic
Immune or protective protein evoked by the presence of foreign substances (antigens)
in the body; each binds to a specific antigen in immune response (AKA
immunoglobulin). - Answer-Antibody
A substance that binds to an antibody; may be foreign or a self-antigen - AnswerAntigen
Portion of an antibody that's specific for a particular antigen; the area of the antibody to
which the antigen binds - Answer-Antigen-binding region
One of the semilunar valves, separating the *left ventricle from the aorta* - AnswerAortic valve
Process by which a cell undergoes *programmed cell death* in a highly organized
manner in response to either external/internal signals - Answer-Apoptosis
Peripheral portion of the skeleton consisting of arms, legs, and pelvic and pectoral
girdles - Answer-Appendicular skeleton
The *central cavity in the gastrula stage* of embryological development; it is lined by
endoderm and ultimately gives rise to the adult digestive tract - Answer-Archenteron
Small arterial structures that link the arteries to the capillaries - Answer-Arterioles
Thick-walled, muscular blood vessel that generally carries blood away from the heart -
Answer-Artery
Cartilaginous coating at the ends of bones that provides a smooth surface for
articulation of bones within a joint - Answer-Articular cartilage
Any reproductive process that does *not* involve the fusion of gametes (such as
budding) - Answer-Asexual reproduction
*Star-shaped structures* that form around the centrosome during mitosis - AnswerAsters
One of two paired structures on either side of the heart, into which blood returning from
either the body (right atrium) or the lungs (left atrium) flows - Answer-Atrium
Form of cell-cell communication in which a cell releases substance that then binds to
the membrane of the releasing cell to either inhibit or activate a cellular activity -
Answer-Autocrine
Inappropriate immune response that *targets self-antigens* - Answer-Autoimmunity
Subdivision of the peripheral NS responsible for involuntary activities, which is further
subdivided into the parasympathetic and sympathetic nervous systems - AnswerAutonomic nervous system
Any chromosome other than a sex chromosome - Answer-Autosome
Midline structures of the skeleton including skull, vertebral column, and ribcage;
provides the central framework of the body - Answer-Axial skeleton
The long fiber of a neuron; it conducts impulses away from the cell body toward the
synapse - Answer-Axon
Transition point between cell body (soma) and axon of a neuron; the site of action
potential initiation - Answer-Axon hillcock
*Rod*-shaped bacterium - Answer-Baccilus
A virus that invades bacteria and sometimes uses bacterial RNA and ribosomes to selfreplicate - Answer-Bacteriophage
Type of granulocytic leukocyte that largely participates in *allergic reactions* and *local
inflammation* - Answer-Basophil
A solution of salts, pigments, and cholesterol produced by liver & stores in gallbladder; it
emulsifies large fat droplets when secreted into the small intestine via the bile duct -
Answer-Bile
Product of the *breakdown of hemoglobin* that is modified to a *more soluble* form in
the liver - Answer-Bilirubin
A type of *asexual* reproduction characteristic of *prokaryotes* in which there is *equal*
nuclear and cytoplasmic division - Answer-Binary fission
The *fluid-filled* central cavity of the *blastula* - Answer-Blastocoel
A mammalian blastula, consisting of the trophoblastic cells and an inner cell mass -
Answer-Blastocyst
The early embryonic stage during which the embryo is a hollow, fluid-filled sphere of
undifferentiated cells - Answer-Blastula
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