Section 30.3 (Exam 2)

Question 1

Ecdysozoans are a major ______________ group.

Answer 1

protostome

Question 2

There are two ways ecdysozoans can be classified. There are those with and those without ______.

Answer 2

limbs

Question 3

Name some limbless ecdysozoans.

Answer 3

Nematodes

Question 4

Name some limbed ecdysozoans.

Answer 4

Tardigrades, velvet worms, and arthropods

Question 5

Nematodes are also known as _______________?

Answer 5

roundworms

Question 6

Describe the nematode cuticle.

Answer 6

Unsegmented, thick, and multilayered

Question 7

How do nematodes perform gas and nutrient exchange?

Answer 7

Gas and nutrient exchange occurs through the cuticle and the gut wall (only one cell thick).

Question 8

How does a nematode move materials through its gut?

Answer 8

The pharynx, a muscular anterior organ, moves materials through the gut.

Question 9

How big are nematodes?

Answer 9

Many are microscopic, but the largest one is 9 meters, which is a parasite in the placenta of a female sperm whale.

Question 10

What are three modes of nutrition among nematodes?

Answer 10

Scavengers, predators, and parasites

Question 11

Many nematodes are ___________ of domestic plants and economically important animals.

Answer 11

parasites

Question 12

Why is Caenorhabitis elegans used as a model organism in genetics and developmental biology research?

Answer 12

It is easy to cultivate, matures in 3 days, and has a fixed number of body cells.

Its genome has been completely sequenced.

Question 13

Name some parasitic diseases that nematodes can cause.

Answer 13

Trichinosis and elephantiasis

Question 14

What is the name of the model organism in genetic and developmental biology research?

Answer 14

Caenorhabitis elegans