Arthropods and Deuterostomes

These flashcards cover key concepts about phylum Arthropoda, deuterostomes, and the characteristics of vertebrates and mammals.

What are the three major lineages of Phylum Arthropoda?

Chelicerates, Myriapods, Pancrustaceans.

What components make up the body plan of arthropods?

Segmented body, hard exoskeleton made of chitin, molting, and paired jointed appendages.

What type of organisms fall under Chelicerates?

Scorpions, spiders, and dust mites.

What are the two main types of Myriapods mentioned?

Millipedes and centipedes.

What are some examples of crustaceans?

Lobsters, crabs, shrimp, pill bugs, barnacles.

What are the three regions of an insect's body?

Head, thorax, and post-genital region.

What is complete metamorphosis in insects?

A developmental process that includes stages: larva (caterpillar), pupa, and adult.

Why were arthropods among the first animals to colonize land?

Their exoskeleton provided structural support and reduced water loss.

In Deuterostomia, what forms the anus during development?

The blastopore.

What unique feature do echinoderms possess?

A water vascular system that branches into tube feet.

What characters define chordates?

Notochord, dorsal hollow nerve cord, pharyngeal slits, post-anal tail.

What is a characteristic of vertebrates?

Chordates with a backbone.

What are gnathostomes?

Vertebrates that have jaws with teeth.

What are the derived characteristics of tetrapods?

Four limbs with digits, a neck, and the absence of gills (except in some aquatic species).

What are amniotes?

Tetrapods that have a terrestrially adapted egg (amniotic egg).

What distinguishes mammals from other amniotes?

Mammals have hair and produce milk.

What are the three major lineages of mammals?

Monotremes, marsupials, and eutherians (placental mammals).

What is a defining feature of marsupials?

They give birth early in development and finish growing while nursing in the marsupium.