chapter 30 - Protostome Animals Overview

These flashcards cover key concepts regarding protostome animals, including their characteristics, classifications, and ecological significance.

What are the three smaller clades that Bilateria is divided into?

Lophotrochozoans, Ecdysozoans, and Deuterostomes.

What characterizes protostomes in terms of their embryonic development?

The blastopore of the gastrula becomes the mouth of the digestive tract.

Lophotrochozoans are partly identified by which two structures?

Lophophore and trochophore larvae.

What type of habitat do flatworms (Phylum Platyhelminthes) occupy?

Marine, freshwater, and damp terrestrial environments.

What is the function of the flame cells in the excretory system of flatworms?

They help filter waste and maintain osmotic balance.

What is the main reproductive strategy of free-living flatworms?

Most are sexual; however, they can reproduce asexually through fission.

How do tapeworms obtain nutrients from their host?

They absorb nutrients through their body from the host's digested food.

What is the significance of the proglottids in tapeworms?

They are body sections composed entirely of reproductive organs.

What class do leeches belong to?

Class Hirudinea.

How do arthropods differ from other animal groups in terms of their body plan?

They exhibit segmentation and jointed appendages.

What is ecdysis in ecdysozoans?

The shedding and regrowing of the tough exterior (cuticle) as the organism enlarges.

What is a unique feature of hexapods?

They have three body segments (head, thorax, abdomen) and three pairs of legs.

What role do insects play in agricultural ecosystems?

They serve as primary pollinators.

What are tardigrades commonly known as?

Water bears.

How many species of arthropods are described?

Over 1.2 million species.