Protostomes and Deuterostomes Lecture Review

This set covers the classification, characteristics, and evolutionary innovations of Protostomes and Deuterostomes, including specific phyla such as Arthropoda, Nematoda, Echinodermata, and Chordata.

Protostome

A developmental pathway where the first hole formed becomes the mouth.

Ecdysis

A Greek word meaning 'slip out' or 'escape'; refers to the periodic shedding of the cuticle in insects and other arthropods or the outer epidermal layer in reptiles.

Elephantiasis

A condition caused by a roundworm transmitted via mosquito bite, leading to the blockage of lymph nodes and fluid accumulation.

Trichinosis

A parasitic disease caused by the nematode $Trichinella \text{ spiralis}$, often acquired by eating undercooked pork.

Arthropoda Traits

Characterized by a segmented body, exoskeleton composed of chitin, jointed appendages, compound eyes, and antennae.

Myriapoda

A lineage within Arthropoda that includes millipedes and centipedes.

Chelicerata

A lineage within Arthropoda including spiders, ticks, horseshoe crabs, and scorpions; notable for having no metamorphosis.

Crustacean

A lineage within Arthropoda that includes lobsters, shrimps, and crabs.

Deuterostomes

A lineage characterized by being triploblasts, having a coelom, and a shared developmental pathway where the anus forms first.

Echinodermata

Marine animals that exhibit radial symmetry as adults but bilateral symmetry as larvae.

Echinoderm Endoskeleton

A hard, spiny structure for support made of plates of calcium carbonate.

Water Vascular System

A key feature of Echinoderms used to operate tube feet.

Dorsal Hollow Nerve Cord

A bundle of nerves that, in vertebrates, becomes the spinal cord and brain.

Notochord

A stiff, supportive rod along the body that is a precursor to vertebrae in chordates.

Perforated Pharynx

Openings in the throat for breathing; in air-breathing vertebrates, these are only present in embryonic stages or larvae.

Muscular Post-Anal Tail

One of the five synapomorphies of Chordata that evolved in an aquatic environment.

Vertebrata Synapomorphies

The presence of a cranium (skull) and vertebrae.

Agnatha

Jawless vertebrates including Hagfish and Lampreys.

Hagfish

A jawless vertebrate with a skeleton made of cartilage, a notochord, and cranium, but no vertebrae; known for slime that is $10 \times$ stronger than nylon.

Lamprey

A jawless vertebrate with a cartilaginous skeleton and rudimentary vertebrae; sometimes parasitic feeding on fish.

Evolution of Jaws

Jaws evolved from paired gill arches between gill slits and allow fish to capture and hold larger prey.

Chondrichthyes

A group including sharks, skates, and rays characterized by a cartilaginous skeleton and jaws, but no bone.

Osteichthyes

Commonly known as 'bony fishes,' containing the lineages Actinopterygii and Sarcopterygii.

Actinopterygii

Ray-finned fishes, such as trout, salmon, and perch, characterized by bony rods in their fins.

Sarcopterygii

Lobe-finned fishes, such as the Coelacanth and Lungfish, with fleshy lobes supported by bones.

Tetrapoda

A group including amphibians, mammals, and reptiles that evolved limbs with multiple digits.

Amniotic Egg

A terrestrial egg with four specialized membranes (including the amnion and allantois) that permits nutrition, waste removal, and survival on land.

Placenta

An internal structure in viviparous mammals where the embryo is protected, portable, and develops at a constant temperature.

Parental Care

Any action by a parent, such as lactation in mammals, that improves the ability of offspring to survive.

Endothermic

An adaptation for flight in birds involving internal regulation of body temperature.