Biodiversity & Classification – Major Animal Phyla & Key Terms

These vocabulary flashcards summarize the key kingdoms, phyla, anatomical terms, and physiological concepts discussed in the lecture on biodiversity and animal classification.

Monera

Domain of prokaryotic organisms with peptidoglycan cell walls; includes true bacteria.

Archaea

Domain of prokaryotes lacking peptidoglycan in cell walls; often inhabit extreme environments.

Protista

Kingdom of mostly unicellular eukaryotes; autotrophic or heterotrophic.

Fungi

Kingdom of absorptive heterotrophic eukaryotes with chitinous cell walls.

Plantae

Eukaryotic kingdom of multicellular, photosynthetic autotrophs with cellulose cell walls.

Animalia

Eukaryotic kingdom of multicellular, ingestive heterotrophs that develop from embryos.

Prokaryotic cell

Cell lacking a membrane-bounded nucleus and organelles.

Eukaryotic cell

Cell possessing a true nucleus and membrane-bounded organelles.

Peptidoglycan

Complex polysaccharide forming bacterial cell walls.

Chitin

Nitrogen-containing polysaccharide composing fungal cell walls and arthropod exoskeletons.

Cellulose

Structural polysaccharide forming plant cell walls.

Autotroph

Organism that synthesizes organic food from inorganic substances.

Heterotroph

Organism that obtains organic food by ingestion, absorption, or combination.

Multicellularity

Condition of being composed of many specialized cells working together.

Phylum Porifera

Sessile, asymmetrical or radial sponges with pores, no tissues, and calcium or silica spicules.

Ostia

Numerous small pores through which water enters a sponge’s body.

Osculum

Large exit pore where water leaves a sponge.

Pinacocyte

Flat external cell forming the outer layer of a sponge.

Mesohyle

Gel-like middle layer in sponges containing amoeboid cells.

Choanocyte

Collar cell lining the spongocoel; drives water flow and captures food.

Gemmule

Resistant capsule of amoeboid cells enabling a sponge to survive harsh conditions.

Phylum Cnidaria

Diploblastic, radial marine animals with cnidocytes; includes jellyfish, corals, hydra.

Cnidocyte

Stinging cell characteristic of cnidarians; houses a nematocyst.

Nematocyst

Explosive organelle in cnidocytes used for defense and prey capture.

Diploblastic

Body derived from two germ layers: ectoderm and endoderm.

Gastrovascular cavity

Blind sac in cnidarians for digestion and circulation with a single opening.

Polyp

Sessile, cylindrical cnidarian body form that reproduces asexually.

Medusa

Free-swimming, umbrella-shaped cnidarian form that reproduces sexually.

Phylum Platyhelminthes

Dorsoventrally flattened, acoelomate flatworms; many parasitic.

Acoelomate

Animal lacking a body cavity; space filled with parenchyma.

Bilateral symmetry

Body plan with left and right halves that are mirror images.

Flame cell

Bulb cell with cilia in flatworms; part of excretory protonephridia.

Protonephridia

Network of tubules and flame cells for osmoregulation in flatworms.

Hermaphrodite

Individual possessing both male and female reproductive organs.

Phylum Nematoda

Unsegmented roundworms with pseudocoelom; many parasitic.

Pseudocoelom

Fluid-filled body cavity not completely lined by mesoderm.

Sensory papillae

Hair-like sensory structures near nematode lips.

Phylum Mollusca

Soft-bodied coelomates with mantle, muscular foot, and often a shell.

Mantle

Epithelial sheath in molluscs that secretes the shell and encloses the mantle cavity.

Mantle cavity

Space between mantle and visceral mass housing gills, anus, and excretory openings.

Radula

Rasping tongue-like feeding organ of most molluscs (absent in bivalves).

Open circulatory system

Blood leaves vessels to bathe tissues directly in sinuses.

Nephridia

Paired excretory tubules of molluscs that empty into mantle cavity.

Phylum Annelida

Segmented worms with metameric segmentation and setae.

Metameric segmentation

Repetition of body units (segments) each with similar organs.

Setae

Chitinous bristles on annelid segments aiding locomotion (absent in leeches).

Metanephridia

Ciliated funnel excretory organs in annelids; one pair per segment.

Closed circulatory system

Blood remains within vessels, as in annelids and vertebrates.

Phylum Arthropoda

Joint-legged animals with chitinous exoskeleton and segmented bodies.

Tagmata

Fused body regions (head, thorax, abdomen) in arthropods.

Exoskeleton

External chitinous covering providing protection and attachment for muscles.

Ecdysis

Shedding and replacement of the arthropod exoskeleton; molting.

Hemocoel

Primary body cavity of arthropods filled with hemolymph.

Hemolymph

Colorless blood of arthropods lacking hemoglobin.

Trachea (arthropod)

Air tubes opening via spiracles for gas exchange in terrestrial arthropods.

Malpighian tubules

Excretory structures of insects and spiders that secrete uric acid into gut.

Phylum Echinodermata

Marine deuterostomes with radial adults, calcareous endoskeleton, water-vascular system.

Ossicle

Calcareous plate forming the echinoderm endoskeleton and spines.

Water vascular system

Network of canals in echinoderms used for locomotion, feeding, and respiration.

Madreporite

Sieve-like opening of the water vascular system regulating water entry.

Tube foot

Fluid-filled extension of water vascular system used in echinoderm movement and attachment.

Deuterostome

Animal in which the blastopore becomes the anus (e.g., echinoderms).

Protostome

Animal in which the blastopore becomes the mouth (e.g., molluscs, annelids, arthropods).

Coelomate

Animal with a true, mesoderm-lined body cavity.