AP Intermediate Zoology (BIEAP) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Binomial nomenclature

A two-part naming system where the genus is capitalized and the species epithet is lowercase, both italicized, providing a universal scientific name for each organism.

Coelom

A fluid-filled body cavity completely lined by mesoderm, distinguishing coelomates such as annelids and vertebrates from pseudocoelomates and acoelomates.

Cnidocytes

Specialized cells unique to Cnidaria that contain nematocysts, coiled stinging organelles used for prey capture and defense.

Notochord

A flexible rod of mesodermal cells along the dorsal side of chordate embryos; in vertebrates it is replaced by the vertebral column during development.

Sliding filament theory

Explanation of muscle contraction in which myosin heads bind actin and pull filaments past each other, shortening the sarcomere; requires ATP and calcium ions.

Haversian system

The structural unit of compact bone consisting of concentric lamellae around a central canal containing blood vessels and nerves, connected by canaliculi.

Saltatory conduction

Rapid propagation of action potentials by jumping between nodes of Ranvier along myelinated axons, increasing conduction velocity compared with unmyelinated fibers.

Countercurrent exchange

A mechanism in fish gills where blood flows opposite to water, maintaining a concentration gradient that maximizes oxygen uptake across the entire gill surface.

Homeostasis

The maintenance of a stable internal environment through negative feedback loops involving sensors, control centers, and effectors that counteract deviations from set points.

Resting membrane potential

The electrical potential difference across a neuron membrane at rest, typically about −70 mV, maintained by the sodium-potassium pump and selective ion permeability.

Osmoregulation

The process by which animals regulate water and solute balance; freshwater fish excrete dilute urine, while marine bony fish drink seawater and excrete excess salts.

Loop of Henle

A U-shaped nephron segment that creates a concentration gradient in the renal medulla, enabling production of concentrated urine in mammals and birds.

Spermatogenesis

The process in seminiferous tubules where diploid spermatogonia undergo meiosis to form haploid spermatids, which mature into spermatozoa.

Cortical reaction

A slow block to polyspermy in which fertilization triggers cortical granules to release enzymes that modify the zona pellucida, preventing additional sperm entry.

Gastrulation

The embryonic process that reorganizes the blastula into three germ layers-ectoderm, mesoderm, and endoderm-establishing the body plan.

Corpus luteum

A temporary endocrine structure formed from the ruptured follicle after ovulation; it secretes progesterone to maintain the uterine lining during early pregnancy.

Semiconservative replication

DNA replication mode in which each new double helix contains one original parental strand and one newly synthesized strand, ensuring faithful genetic transmission.

Frameshift mutation

A mutation caused by insertion or deletion of nucleotides not in multiples of three, shifting the reading frame and altering all downstream amino acids.

Lac operon

A gene regulatory system in bacteria where lactose acts as an inducer, binding the repressor and allowing transcription of lactose-metabolizing genes when glucose is scarce.

Hardy-Weinberg equilibrium

A principle stating that allele and genotype frequencies remain constant in a large, randomly mating population without mutation, migration, or selection.

Homologous structures

Anatomical features in different species that share common ancestry despite possibly different functions, such as the forelimbs of vertebrates.

Fixed action pattern

An innate, stereotyped sequence of behaviors triggered by a specific sign stimulus and carried to completion once initiated, even if the stimulus is removed.

Kin selection

A form of natural selection favoring behaviors that increase the reproductive success of relatives, thereby enhancing inclusive fitness of the actor.

Carrying capacity

The maximum population size an environment can sustain indefinitely, determined by available resources; symbolized K in the logistic growth model.

Biomagnification

The increasing concentration of persistent toxic substances, such as DDT or mercury, in organisms at successively higher trophic levels of a food chain.

Ecological succession

The gradual, directional change in species composition of a community over time, from pioneer species to a stable climax community.

Eutrophication

Nutrient enrichment of water bodies, often by runoff, causing excessive algal growth, oxygen depletion, and harm to aquatic animal life.

Apiculture

The management of honeybee colonies for honey, beeswax, and pollination services, involving species such as Apis indica and Apis mellifera.

Sericulture

The rearing of silkworms, especially Bombyx mori, for silk production; the life cycle includes egg, larva, pupa, and adult stages.

Hypophysation

Induced breeding technique in fish where pituitary gland extract is injected to stimulate spawning in species that do not breed naturally in captivity.

Transgenic animal

An animal whose genome has been altered by the introduction of foreign DNA, often through microinjection or viral vectors, for research or production purposes.

DNA fingerprinting

A technique using variable repeat sequences in DNA to produce a unique pattern for each individual, applied in forensics and paternity testing.