Kaplan Glossary (vocab) Flashcards
adaptive radiation
the production of a number of different species from a single ancestral species
ADH
a hormone that regulates water reabsorption by the kidney
adipose
fatty tissue, fat-storing tissue, or fat within cells
adrenal cortex
outer part of the adrenal gland that secretes many hormones, including cortisone and aldosterone
adrenaline (epinephrine)
an “emergency” hormone stimulates by anger or fear, increases blood pressure and heart Rae in order to supply the emergency needs of the muscles
ACTH
secreted by anterior pituitary gland; stimulates the adrenal cortex to produce its characteristic hormones
aldosterone
hormone active in osmoregulation; a mineral corticoid produced by the adrenal cortex; stimulates reabsorption of Na+ and secretion of K+
allantois
the extra-embryonic membrane of birds, reptiles, and mammals that serves as an area of gaseous exchange and as a site for the storage of noxious exertion products
amnion
the extra-embryonic membranes in birds, reptiles, and mammals that surrounds the embryo, forming an amniotic sac
androgen
a male sex hormone (ie testosterone)
angiosperm
a flowering plant that produces seeds included in an ovary and is characterized by the presence of fruits and flowers
Annelida
the phylum to which segmented worms belong
anther
the part of the male reproductive organ (the stamen) that produces and stores pollen
antibody
globular proteins produced by B cells that destroy or inactivate antigens
acetylcholine
a transmitter substance released from the axons of nerve cells at the synapse
aortic arch
blood vessel located between ascending and descending aortas that delivers blood to most of upper body
appendage
a structure that extends from the trunk of an organism and is capable of active movements
aqueous humor
fluid in the eye, found between the cornea and the lens
Arachnida
a class of arthropods that includes scorpions, spiders, mites, and ticks
artery
a blood vessel that carries blood away from the heart
Arthropoda
the phylum to which jointed legged invertebrates belong, including insects, arachnids, and crustaceans
assimilation
the conversion of digested foods and other materials into forms usable by the body (i.e. the conversion of amino acids into proteins)
atrium
the thin-walled superior chamber of the heart
autolysis
self-digestion occurring in plant and animal tissues, particularly after they have ceased to function properly
autonomic nervous system
the part of the nervous system that regulates the involuntary muscles, such as the walls of the alimentary canal; includes the parasympathetic and sympathetic nervous systems
autosome
any chromosome that is not a sex chromosome
bacillus
bacteria that are rod-shaped
bile salts
compounds in bile that aid in emulsification
binary fission
asexual reproduction; in this process, the parent organism splits into two equal daughter cells
binomial nomenclature
the system of naming an organism by its genus and species names
blastula
a stage of embryonic development in which the embryo consists of a hollow ball of cells
bud
in plants, an area of undifferentiated tissue covered by embryonic leaves
budding
a process of asexual reproduction in which the offspring develop from an outgrowth of the plant or animal
buffer
a substance that prevents appreciable changes in pH in solutions to which small quantities of acids or bases are added
calorie
a unit of heat; the amount of heat required to raise the temperature of 1 gram of water by 1 degree centigrade
cambium
undifferentiated tissue in the stem of a plant that aids growth in width
carapace
a bony or chitinous case or shield covering the back or part of the back of an animal (e.g. the shell of a crab)
carotene
an orange plant pigment that is the precursor of vitamin A
cation
an ion with a positive charge, or an ion that migrates toward the cathode (negative electrode) in an electric field
cell wall plate
in mitosis of higher plants, the structure that forms between the divided nuclei of the two daughter cells and eventually becomes the cell wall
central nervous system (CNS)
encompasses the brain and the spinal cord
centriole
the small granular body within the centrosome to which the spindle fibers attach
centromere
the place of attachment of the mitotic fiber to the chromosome
centrosome
a structure in animal cells containing centrioles from which the spindle fibers develop
cephalic
pertaining to the head
cerebellum
the hindbrain region that controls equilibrium and motor coordination
cerebrum
the largest portion of the human brain; it is believed to be the center of intelligence and conscious thought
chemosynthesis
the process by which carbohydrates are formed through chemical energy; found in bacteria
chemotropism
the orientation of cells or organisms in relation to chemical stimuli; the growth or movement responsible of organisms to chemical stimuli
chitin
a white or colorless, amorphous, horny substance that forms part of the outer integument of insects, crustaceans, and some other invertebrates; it occurs in certain fungi
chlorophyll
a green pigment that performs essential functions as an electron donor and light entrapper in photosynthesis
Chordata
an animal phylum in which all members have a notochord, dorsal nerve cord, and pharyngeal gill slits at some embryonic stage
chorion
the outermost, extra-embryonic membrane of reptiles and birds
chyme
partially digested food in the stomach
circadian rhythms
daily cycles of behavior
cleavage
the division of animal cell cytoplasm caused by the pinching in of the cell membrane
climax community
the stable, biotic part of the ecosystem in which populations exist in balance with each other and with the environment
cloaca
the chamber in the alimentary canal of certain vertebrates located below the large intestine, into which the ureter and reproductive organs empty (as in frogs)
cochlea
the sensory organ of the inner ear of mammals; it is coiled and contains the organ of Corti
codominant
the state in which two genetic traits are fully expressed and neither dominates
Cnidarias
an invertebrate animal phylum in which animals possess a single alimentary opening and tentacles with stinging cells; examples are jellyfish, corals, sea anemones, and hydra
coelom
the space between the mesodermal layers that forms the body cavity of some animal phyla
coenzyme
an organic cofactor required for enzyme activity
conditioning
the association of a physical, visceral response with an environmental stimulus with which is not naturally associated; a learned response
cone
a cell in the retina that is sensitive to colors and is responsible for color vision
contractile vacuole
a specialized structure that controls osmotic pressure by removing water from the cell; exists in protozoans
cornea
the outer, transparent layer of the eye
corpus callosum
a tract of nerve fibers connecting the two cerebral hemispheres
corpus luteum
a remnant of the follicle after ovulation that secretes the hormone progesterone
cortisone
a hormonal secretion of the adrenal cortex
cotyledon
a “seed leaf”; responsible for food storage in a plant embryo
cretinism
a thyroid deficiency that results in stunted growth and mental disabilities
cuticle
a waxy protective layer secreted by the outer surface of plants and insects
cytochrome
a hydrogen carrier containing iron that functions in many cellular processes, including respiration
deamination
the removal of an amino group from an organism, particularly from an amino acid
deme
a small, local population
diastole
dilation of the cavities of the heart that allows to fill with blood; followed by systole (contraction)
diencephalon
the hind portion of the forebrain of vertebrates
differentiation
a progressive change from which a permanently more mature or advanced state results; for example, a relatively unspecialized cell’s development into a more specialized one
dimorphism
the instance of polymorphism in which there is a difference of form between two members of species, as between males and females
disjunction
the separation of homologous paris of chromosomes following meiotic synapse
dorsal root
the sensory branch of each spinal nerve
embolus
a blood clot that is formed within a blood vessel
emulsion
a colloidal system involving the dispersion of a liquid within a liquid
endemic
pertaining to a restricted locality; ecologically, occurring only in one particular region
endocrine gland
a ductless gland that secretes hormones directly into the bloodstream
endocytosis
a process by which the cell membrane is invaginated to form a vesicle that contains extracellular medium
endoplasm
the inner portion of the cytoplasm of a cell or the portion that surrounds the nucleus
endosperm
the triploid tissue in some seeds that contains stored food and is formed by the union of one sperm nucleus with two nuclei of the female’s gametophyte
epicotyl
the portion of seed plant embryo above the cotyledon
epithelium
the cellular layer that covers external and internal surfaces
epiphyte
a plant that lives on another plant commensalistically
estrogen
a female sex hormone secreted by the follicle
eustachian tube
an air duct from the middle ear to the throat that equalizes external and internal air pressure
exocytosis
a process by which a vesicle in the cell fuses with the cell membrane and releases its contents to the outside
fallopian tube
the mammalian oviduct that leads from the ovaries to the uterus
feedback mechanism
the process by which a certain function is regulated by the amount of the substance it produces
femur
the thigh bone of vertebrates
fibrin
protein threads that form in the blood during clotting
follicle
the sac in the ovary in which the egg develops
FSH
a hormone released by the anterior pituitary hormone that stimulates the follicles in females and the function of the seminiferous tubules in males
food vacuole
a vacuole in the cytoplasm in which digestion takes place (in protozoans)
gallbladder
an organ that stores bile
gametophyte
the haploid, sexual stage in the life cycle of plants
ganglion
a grouping of neuron cell bodies that acts as a coordinating center
gastrula
a stage of embryonic development characterized by the differentiation of cells into the ectoderm and endoderm germ layers and by the formation of the archenteron; can be two layer or three layer
geotropism
any movement or growth of a living organism in response to the force of gravity
germ cell
a reproductive cell
germ layer
one of the primary tissues of the embryo
glycogen
a starch form in animals; glucose is converted to glycogen in the liver
goiter
an enlargement of the thyroid gland due to lack of iodine
gonads
the reproductive organ that produces sex cells
Graafian follicle
the cavity in the mammalian ovary in which the egg ripens
gymnosperm
a plant that belongs to the class of seed plants in which the seeds are not enclosed in an ovary; includes the conifers
hepatic portal system
the veins that carry blood from the digestive organs to the liver
humerus
a bone of the upper arm
hydrostatic skeleton
fluid skeleton of annelids
hypocotyl
the portion of the embryonic seed plant below the point of attachment of the cotyledon; forms the root
imprinting
the process by which environmental patterns or objects presented to a developing organism during a “critical period” of its growth are accepted as a permanent element of its behavior
incomplete dominance
genetic blending; each allele exerts some influence on the phenotype
inner ear
a fluid-filled sensory apparatus that aids in balance and hearing
insulin
a hormone produced by the pancreas; regulates blood sugar concentration by converting glucose to glycogen
integument
refers to protective covering, such as the covering of an ovule that develops into the seed coat, or to an animal’s skin
interstitial cells
cells that produce sex hormones
irritability
the ability to respond to a stimulus
lactase
the enzyme that acts upon lactose
lacteal
a lymph tubule located in the villus that absorbs fatty acids
larva
a period in the development of animals between the embryo and adult stages; starts at hatching and ends at metamorphosis
lichen
an association between an algae and a fungus that is symbiotic and mutualistic in nature
linkage
occurs when different traits are inherited together more often that they would have been by chance alone; it is assumed that these traits are linked (near each other) on the same chromosome
lipase
a fat-digesting enzyme
littoral zone
a marine biome; a region on the continental shelf that contains an ocean area with depths of up to 600ft
LH
a hormone secreted by the anterior pituitary gland that stimulates the secretion of progesterone by the corpus luteum; also stimulates the secretion of sex hormones by the testes
macula
a sensory hair structure in the utriculus and the sacculus of the inner ear; orients the head with respect to gravity
malleus (hammer)
the outermost bone of the middle ear
Malpighian tubules
tubules that excrete metabolic wastes into the hind gut in arthropods
maltase
an enzyme that acts upon maltose and converts it into glucose
medulla oblongata
the posterior part of the brain that controls the rate of breathing and other autonomic functions
meninges
three membranes that envelop the brain and spinal cord
meristem
an undifferentiated, growing region of a plant that is constantly undergoing cell division and differentiation
morula
the solid ball of cells that results from cleavage of an egg; precedes the blastula stage
mucosa
a mucus-secreting membrane, such as the inner intestinal lining
nerve
a bundle of nerve axons
nictitating membrane
a thin, transparent, eyelid-like membrane that opens and closes laterally across the cornea of many vertebrates (the “third eyelid”)
nucleolus
a dark-staining small body within the nucleus; manufactures RNA
oviduct
a tube connecting the ovaries and the uterus
oxidation
the removal of hydrogen or electrons from a compound or addition of oxygen
pairing (synapsis)
an association of homologous chromosomes during the first meiotic division
parasympathetic
pertaining to a subdivision of the autonomic nervous system of vertebrates
parenchyma
plant tissue consisting of large, thin walled cells for storage
parthenogenesis
a form of asexual reproduction in which the egg develops in the absence of sperm
pelagic zone
a marine biome typical of the open seas
pepsin
a stomach enzyme that partially digests proteins
peripheral nervous system
comprises somatic and autonomic nervous system; consists of cranial nerves and spinal nerves
peristalsis
waves of contraction and relaxation passing along a tubular structure, such as the digestive tube
pheromone
substance secreted by organisms that influences the behavior of other members of the same species
phloem
the vascular tissue of a plant that transports organic materials (photosynthetic products) from the leaves to other parts of the plant
photolysis
a process of photosynthesis in which whiter is split into H+ and OH-; the hydrogen ion is then jointed to NADP
pinocytosis
the intake of fluid droplets into a cell
pistil
the part of the flower that bears the female gametophyte
pith
the central tissue of a stem, used for food storage
placenta
a structure formed by the wall of the uterus and the chorion of the embryo; serves as the area in which the embryo obtains nutrients from the parent
planaria
a class of free-living flatworms
plexus
a network, particularly of nerves or blood vessels
polymorphism
the individual differences of form among the members of a species
Porifera
the phylum of sponges
progesterone
hormone whose function is to maintain the endometrium
Protista
a kingdom of unicellular living organisms that are neither animals nor plants; includes some groups of algae, slime molds, and protozoa
ptyalin
a digestive enzyme of the saliva that turns starch into maltose (salivary amylase)
purine
adenine or guanine
pyrimidine
cytosine, thymine, or uracil
pyloric valve
a muscular valve regulating the flow of food from the stomach to the small intestine
rhodopsin
the pigment in rod cells that causes light sensitivity
rickettsia
a kind of microorganism that is between a virus and a bacterium; parasitic within the cells of insects and ticks
rod
a cell in the retina that is sensitive to weak light
saprophyte
an organism that obtains its nutrients from dead organisms
secondary tissue
tissue formed by the differentiation of cambium that causes a growth in width of a plant stem
semicircular canals
fluid-filled structures in the inner ear that are associated with the sense of balance
seminiferous tubules
structures in the testes that produce sperm and semen
sensory neuron
a neuron that picks up impulses from receptors and transmits them to the spinal cord
sere
a series of ecological communities formed in ecological succession
sinus
a space in the body
somatic cell
any cell that is not a reproductive cell
spiracle
the external opening of the trachea in insects, opening into the respiratory system
spore
a reproductive cell that is capable of developing directly into a haploid organism
sporophyte
an organism that produces spores; a phase that alternates with the gametophyte phase
stamen
the part of the flower that produces pollen
steroid
one of the classes of organic compounds; includes cholesterol, sex hormones, ACTH, and vitamin D
stigma
the uppermost portion of the pistil upon which pollen grains alight
style
a stalklike or elongated body part, usually pointed at one end; part of the pistil of the flower
substrate
a substance that is acted upon by an enzyme
sucrase
an enzyme that acts upon sucrose
sympathetic
pertaining to a subdivision of the autonomic nervous system
synapsis
the paring of homologous chromosomes during meiosis
systol
the contraction of the atria or ventricles of the heart
taiga
a terrestrial habitat zone that is characterized by large tracts of coniferous forests, long and cold winters, and short summers; bounded by tundra in the north an found particularly in Canada, northern Europe, and Siberia
tetrad
a pair of chromosome pairs present during the first metaphase of mitosis
thrombin
a substance that participates in clotting of blood in vertebrates; formed from prothrombin; it converts fibrinogen into fibrin
thrombokinase
the enzyme released from the blood platelets in vertebrates during clotting
thymus
a ductless gland in the upper chest region; concerned with immunity and the maturation of lymphocytes
thyroxine
a hormone of the thyroid; regulates basal metabolism
trilobite
a marine arthropod, now extinct, that lived during the Paleozoic era
trypsin
an enzyme from the pancreas that digests proteins in the small intestine
tundra
the biome characterized by a short growing season, no trees, and frozen ground
turgor pressure
the pressure exerted by the contents of a cell against the cell membrane or cell wall
ungulate
a hoofed animal
ureter
a duct that carries urine from the kidneys into the bladder
uterus
an organ in which the fetus develops
vein
a blood vessel that carries blood back to the heart from the capillaries
ventral root
a basal branch of each spinal nerve; carries axons of motor neurons
ventricle
a more muscular chamber of the heart that pump blood to the lungs an to the rest of the body
xylem
vascular tissue of the plant that aids in support and carries water
yolk sac
a specialized structure that leads to the digestive tract of a developing organism and provides it with food during the early development
