VZOO 21 General Zoology Lecture - Vocabulary Flashcards (Animal Biology)

Vocabulary terms and definitions covering major concepts from the notes on animal biology, organization, development, reproduction, and taxonomy.

Eukaryotic

Cells with a true nucleus and membrane-bound organelles; generally larger and more complex than prokaryotes.

Multicellular

Organisms composed of many cells with specialized functions that are interdependent.

Heterotrophs

Organisms that obtain energy by consuming organic molecules rather than making them.

Autotrophs

Organisms that synthesize their own organic molecules from sunlight or inorganic sources.

Aerobic respiration

Energy production that uses O2; yields maximum energy from glucose (about 36–38 ATP).

Anaerobic respiration

Energy production without O2; produces less energy (about 2 ATP per glucose).

Mitochondria

Cellular organelles that generate most ATP through aerobic respiration; energy factories of the cell.

Ribosomes

Protein-synthesizing organelles; numerous in animal cells.

Lysosomes

Organelles that digest waste and broken-down cell components.

Epithelium

Tissue that lines surfaces and forms coverings; provides protection, absorption, secretion.

Connective tissue

Tissue with abundant extracellular matrix; supports, binds, stores energy; often highly vascularized.

Muscle tissue

Contractile tissue enabling movement; provides force and heat generation.

Nervous tissue

Tissue of neurons forming networks to transmit electrical impulses.

Integumentary system

Skin and its derivatives; outer covering providing protection and sensory input.

Endoskeleton

Internal skeleton that grows with the body (e.g., vertebrates).

Exoskeleton

External skeleton; provides protection and support (e.g., arthropods; molts in many groups).

Hydrostatic skeleton

Fluid-filled body cavity used with muscle action to produce movement (common in soft-bodied animals).

Open circulatory system

Circulatory system where the body cavity is not completely enclosed in vessels; hemolymph bathes tissues.

Closed circulatory system

Blood is contained within vessels and pumped by a heart; typical of vertebrates.

Respiratory system

Organs for gas exchange (gills, lungs, etc.) often linked to circulatory system.

Digestive system

System that breaks down food and absorbs nutrients; includes GI tract and accessory organs.

Alimentary canal

Complete digestive tract from mouth to anus with a continuous tube.

Coelom

Body cavity lined by mesoderm; true body cavity separating gut from body wall.

Acoelomate

Organisms with no true body cavity.

Pseudocoelomate

Body cavity that is false or partially lined with mesoderm.

Eucoelomate

True coelom; body cavity completely lined with mesoderm.

Protostomes

Embryos where the blastopore becomes the mouth; includes spiral cleavage and schizocoely; mosaic (deterministic) development.

Deuterostomes

Embryos where the blastopore becomes the anus; includes enterocoely; radial cleavage; regulative development.

Blastula

Early embryo stage; hollow ball of cells produced after cleavage.

Gastrulation

Process forming germ layers (ectoderm, endoderm, mesoderm) via invagination of the blastula.

Germ layers

Three primary layers: ectoderm (outer), endoderm (inner), mesoderm (middle).

Ectoderm

Outer germ layer; forms skin and nervous system.

Endoderm

Inner germ layer; lines digestive and respiratory tracts; forms associated organs.

Mesoderm

Middle germ layer; gives rise to muscles, skeleton, circulatory system, and more.

Notochord

Flexible rod in chordate embryos; a key deuterostome feature.

Dorsal neural tube

Embryonic structure that develops into brain and spinal cord; chordate hallmark.

Pharyngeal gill pouches

Embryonic pharyngeal structures that become gills/slits in many chordates.

Amniotic egg

Egg of reptiles, birds, and mammals with four extraembryonic membranes allowing terrestrial development.

Amnion

Innermost embryonic membrane that surrounds the embryo in a fluid-filled sac.

Chorion

Outer extraembryonic membrane; involved in gas exchange and, with allantois, forms the chorioallantoic membrane.

Allantois

Extraembryonic membrane for waste storage and gas exchange; contributes to placenta in some amniotes.

Yolk sac

Membrane that provides yolk in eggs; in mammals, a source of early blood cells; nutrient source in some contexts.

Amniotes

Group of tetrapods (reptiles, birds, mammals) that lay eggs with amniotic membranes.

Monotremes

Egg-laying mammals (e.g., platypus, echidnas).

Marsupials

Mammals whose embryos complete development in a pouch after a short gestation.

Placental mammals

Mammal group in which development occurs inside the uterus with a placenta.

Placenta

Maternal-fetal organ enabling exchange of nutrients, gases, and wastes.

Ovoviviparity

Eggs hatch inside the mother; embryos are nourished by yolk.

Oviparity

Eggs laid outside the body; nourishment from yolk.

Viviparity

Live birth; offspring develop inside the mother and are nourished directly.

Parthenogenesis

Asexual reproduction where an egg develops without fertilization; offspring may be haploid or diploid.

Hermaphroditism

Individuals possess both male and female reproductive systems; can self-fertilize or mate with others.

Sex determination XY

Genetic system in which males are XY and females are XX (mammals; some insects/plants).

Sex determination ZW

Genetic system where females are ZW and males are ZZ (birds; some reptiles/insects).

Temperature-dependent sex determination

Sex determined by incubation temperature in some reptiles and turtles.

Binomial nomenclature

Two-part Latin name for species: genus (capitalized) + species (lowercase); italicized.

Phylogeny

Evolutionary history or relationships among species.

Homology

Shared characteristics due to common ancestry.

Homoplasy

Shared traits not due to common ancestry (convergent evolution).

Monophyletic

A clade; includes an ancestor and all its descendants.

Paraphyletic

A group containing an ancestor and some, but not all, descendants.

Polyphyletic

A group containing species with different ancestors; not a clade.

Cladogram

Diagram showing evolutionary relationships based on shared derived traits (synapomorphies).