Animal Dissection and Life Cycles

Flashcards for exam review.

Nematoda (e.g., Roundworm – Ascaris) - External

Smooth, tapered body, cuticle-covered.

Nematoda (e.g., Roundworm – Ascaris) - Internal

Mouth → pharynx → intestine → anus (complete digestive system), Long reproductive tubes (females have bigger body), No circulatory/respiratory system

Oligochaeta (e.g., Earthworm) - External

Segmented body, clitellum (band), setae (bristles)

Oligochaeta (e.g., Earthworm) - Internal

Pharynx → esophagus → crop → gizzard → intestine → anus, 5 aortic arches (hearts), closed circulatory system, Ventral nerve cord, nephridia (for excretion)

Cephalopoda (e.g., Squid) - External

Mantle, 8 arms + 2 tentacles, siphon, eyes

Cephalopoda (e.g., Squid) - Internal

Beak, radula (in mouth), Ink sac, Gills, branchial hearts, Pen (internal shell), stomach, liver

Echinodermata (e.g., Sea Star) - External

5 arms (usually), spiny skin, central disc

Echinodermata (e.g., Sea Star) - Internal

Water vascular system: madreporite → ring canal → radial canals → tube feet, Stomach (can extend out of body), digestive glands, Gonads (in each arm)

Uniramia grasshopper

- External

Head, thorax, abdomen, 6 legs, antennae, wings

Uniramia (e.g., Insects – Grasshopper) - Internal

Mandibles (mouthparts), crop, gizzard, stomach, intestine, anus, Open circulatory system, Tracheal tubes for breathing, Malpighian tubules (excretion)

Trematoda (e.g., Flukes) Life Cycle

Egg → miracidium → snail (asexual) → cercaria → vertebrate host (sexual adult)

Cestoda (e.g., Tapeworms) Life Cycle

Egg → intermediate host eats it → larval cyst → definitive host (e.g., human) eats host → adult tapeworm grows in intestine

Polychaeta (e.g., Bristle Worms) Life Cycle

External fertilization → trochophore larva → develops into segmented worm

Hirudinea (e.g., Leeches) Life Cycle

Hermaphroditic reproduction → cocoon with eggs → hatch as small leeches (no larva stage)

Bivalvia (e.g., Clams, Mussels) Life Cycle

Egg → trochophore larva → veliger larva → settles and grows into adult (some use fish hosts)

Uniramia (e.g., Insects) - Complete Metamorphosis

Egg → larva → pupa → adult (e.g., butterflies, beetles)

Uniramia (e.g., Insects) - Incomplete Metamorphosis

Egg → nymph → adult (e.g., grasshoppers)