Chapter 12

Question 1

Members of phylum Onychophora are all _________ and are found in ____ ecosystems.

Answer 1

terrestrial, tropical.

Question 2

The members of phylum Onychophora are distinguished from the other phyla in this chapter by having

Answer 2

a tracheal system.

Question 3

The members of phylum Tardigrada are distinguished from the other phyla in this group by having

Answer 3

cryptobiosis.

Question 4

True or false?
Most members of phylum Tardigrada are considered to be herbivorous feeders and are found in films of water associated with primitive plants.

Answer 4

true

Question 5

True or false?
Onychophorans have annelid-like characteristics such as a muscular body wall and segmentally arranged nephridia, yet arthropod-like characteristics such as a large brain, and a tracheal system.

Answer 5

true

Question 6

True or false?
Traits of onychophorans that are unique include oral papillae, body tubercles for locomotion that are rather ventrally located, and suppression of external segmentation.

Answer 6

true

Question 7

True or false?
Of the Kinorhyncha, Priapulida, Lorcifera, and Onychophora, the only phylum which has members which are fully ambulatory and terrestrial is Onychophora.

Answer 7

true

Question 8

True or false?
Onychophorans have spiracles the are different from those found in annelids, as they cannot close. Therefore, these animals are restricted to moist areas, as water would be lost from the tracheal system in a dry habitat.

Answer 8

true

Question 9

True or false?

Of the groups studied in this chapter, only the onychophorans exhibited viviparity.

Answer 9

true

Question 10

True or false?

Cryptobiosis is best exhibited by the tardigrades, and is induced by unfavorable changes in environmental conditions.

Answer 10

true

Question 11

True or false?

Because of various characters, some researchers have suggested that tardigrades are more aligned with the acoelomates.

Answer 11

false

Question 12

Which one of the pseudocoelomate phyla are tiny marine animals with 11 external segments and recurved spines on the surface for locomotion?

Answer 12

Kinorhyncha

Question 13

Which one of the following pseudocoelomate phyla has members that live between sand grains and can retract their bodies into a circular lorica?

Answer 13

Kinorhyncha

Question 14

The nematodes are unique in that sperm are completely lacking ____.

Answer 14

flagella

Question 15

The nematodes are unique in that motile ________ and ________ are completely lacking.

Answer 15

cilia, flagella

Question 16

Some of the nematodes are successful as endoparasites because their bodies are covered by a

Answer 16

nonliving cuticle.

Question 17

Four examples of parasitic nematodes are hookworms, filarial worms, ________, and ________

Answer 17

pinworms, trichina worms

Question 18

Which one of the following pseudocoelomate phyla has members that are free living as adults, and parasitic in arthropods as juveniles?

Answer 18

Nematomorpha

Question 19

Which one of the following is a colloquial term for a nematomorph?

Answer 19

horsehair worm