Chapter 14

Question 1

All of the following are characteristics of members of the phylum Arthropoda except one. Select the exception.

Answer 1

dorsal nervous system

Question 2

All of the following are Ecdysozoan phyla except one. Select the exception.

Answer 2

Mollusca

Question 3

The outermost waxy layer of the arthropod exoskeleton is called the

Answer 3

epicuticle.

Question 4

A layer of cells that secretes the arthropod exoskeleton is called the

Answer 4

hypodermis

Question 5

To which phyla of animals are arthropods now considered most closely related?

Answer 5

Nematoda

Question 6

Which subphyla of arthropods does not contain any living animals?

Answer 6

Trilobitomorpha

Question 7

Within which phyla of animals has metamerism not evolved?

Answer 7

Nematoda

Question 8

In the region of a joint, the ______ of the exoskeleton is less hardened and forms an articular membrane. In other parts of the exoskeleton this region is hardened and inflexible.

Answer 8

procuticle

Question 9

Biramous appendages are present in, or were present in

Answer 9

Crustacea and Trilobitomorpha.

Question 10

The sensory, feeding, and locomotor tagmata of members of the subphylum Chelicerata is the

Answer 10

prosoma or cephalothorax.

Question 11

The second pair of appendages of members of the subphylum Chelicerata is used in sensory perception, feeding, locomotion, or reproduction. These appendages are called

Answer 11

pedipalps

Question 12

Excretory structures found in many arachnids consist of thin-walled sacs that open to the body surface at pores near the base of posterior appendages. These excretory structures are called

Answer 12

coxal glands.

Question 13

Most arthropods lay eggs that develop outside the body. They are

Answer 13

oviparous

Question 14

Ticks and mites are members of the order

Answer 14

Acarina

Question 15

Harvestmen or daddy longlegs are members of the order

Answer 15

Opiliones

Question 16

Of the subphylum Crustacea, ______ has the largest number of species.

Answer 16

Malacostraca

Question 17

Barnacles are members of the class

Answer 17

Maxillopoda

Question 18

All of the following are crayfish mouth appendages except one. Select the exception.

Answer 18

pleopods

Question 19

Metamorphosis often results in adult and immature stages having different feeding habits and habitats. Metamorphosis, therefore, reduces competition between adult and immature stages and has contributed to the success of the arthropods.

Answer 19

True

Question 20

Metamerism has arisen at least three times in animal evolution.

Answer 20

True

Question 21

Krill are in the class Branchiopoda.

Answer 21

False

Question 22

Arthropods that have just undergone ecdysis are secretive and remain hidden because the new exoskeleton has not yet hardened.

Answer 22

True

Question 23

Book lungs or book gills are present in members of the subphylum Crustacea.

Answer 23

False

Question 24

Scorpions have a period of courtship prior to mating. Mating occurs by copulation and the direct transfer of sperm from the male to the female.

Answer 24

False

Question 25

Members of the class Pycnogonida are the sea spiders. Pycnogonids are dioecious. After eggs are fertilized, they are cemented onto ovigers of the male where they are carried until hatching.

Answer 25

True

Question 26

The appendages of a crayfish are said to be serially homologous because they have evolved from a common ancestral form. The common ancestral form is the biramous appendage, which consists of a protopodite that attaches to the body wall and gives rise to two distal processes.

Answer 26

True

Question 27

In the barnacles, planktonic nauplius larvae attach to the substrate by their first antennae and metamorphose to adults.

Answer 27

False

Question 28

Members of the subphylum Chelicerata were preadapted for terrestrial life by the exoskeleton, which was relatively impermeable to water and supportive on land. Members of the class Arachnida were some of the very early terrestrial inhabitants.

Answer 28

True

Question 29

Members of the subphylum Trilobitomorpha were a dominant form of life in the ocean during the Cambrian period (600 million years ago) to the Carboniferous period (345 million years ago). Today, a few living species of trilobites inhabit deep water along the eastern coast of North America.

Answer 29

False

Question 30

Horseshoe crabs are members of the class Merostomata. Their body form has changed little over the last 200 million years, and they are an excellent example of stabilizing selection.

Answer 30

True