Chapter 15

Question 1

Millipedes belong to the arthropod class

Answer 1

Diplopoda

Question 2

Centipedes belong to the arthropod class

Answer 2

Chilopoda.

Question 3

Members of this class feed on decaying plant matter, possess repugnatorial glands, and possess two pairs of appendages per apparent segment.

Answer 3

Diplopoda

Question 4

Members of this class live in forest-floor litter, where they feed on fungi, humus, and other decaying organic matter. Their body consists of 11 segments and 9 pairs of legs.

Answer 4

Pauropoda

Question 5

The thoracic tagmata of an insect often has a pair of wings on

Answer 5

the mesothorax and metathorax.

Question 6

Insect flight, in which muscles act to change the shape of the exoskeleton during both upward and downward wing beats, is called ______ flight.

Answer 6

asynchronous

Question 7

Which of the following mouthparts of a chewing insect, like a grasshopper, is primarily a sensory, liplike structure and is the anterior-most mouthpart?

Answer 7

labrum

Question 8

The smallest branches of an insect’s respiratory system exchange respiratory gases at the level of body cells. These smallest branches are called

Answer 8

tracheoles

Question 9

Sensory structures found in the legs of crickets, the abdomen of grasshoppers, and the thorax of some moths detect pressure (sound) waves in the air. These sensory structures are called

Answer 9

tympanal organs.

Question 10

The light collecting area of a compound eye that converts light energy into a nerve impulse is called the

Answer 10

rhabdome

Question 11

A ______ is (are) a protective case(s) for the pupal stage of an insect that is formed from the last larval exoskeleton.

Answer 11

puparium and chrysalis

Question 12

Insect development in which immatures are very different from the adult in body form, behavior, and habitat is called ______ metamorphosis.

Answer 12

holometabolous

Question 13

The earliest insects likely exhibited ______________________ metamorphosis.

Answer 13

ametabolous

Question 14

The most successful groups of insects exhibit __________________ metamorphosis.

Answer 14

holometabolous

Question 15

In haplodiploid insects, sisters are related by ______

Answer 15

75%.

Question 16

Mayfly development occurs through a gradual series of changes, but the immatures are very different from the adults. These immatures are called _________________.

Answer 16

naiads

Question 17

Insect development in which molting continues after sexual maturity and in which immatures resemble adults is called ______ metamorphosis.

Answer 17

ametabolous

Question 18

Social insects include those in the orders

Answer 18

Hymenoptera and Isoptera.

Question 19

Myriapoda includes scorpions, centipedes, and proturans.

Answer 19

False

Question 20

The wings of a midge may beat at frequencies of 1,000 cycles per second, which is much faster than the frequency of nerve impulses to flight muscles.

Answer 20

True

Question 21

Insects are not capable of regulating their body temperature.

Answer 21

False

Question 22

Gas exchange in insects involves respiratory pigments dissolved in the hemolymph.

Answer 22

False

Question 23

Insects excrete uric acid using Malpighian tubules, which empty into the gut tract at the junction of the midgut and the hindgut. Because uric acid can be excreted as a semisolid, this excretory mechanism minimizes water loss and aids an insect’s life on land.

Answer 23

True

Question 24

Even though it can be very complex, most insect behavior is the result of reflexes programmed by specific neural connections.

Answer 24

True

Question 25

An insect’s compound eyes probably form images, but more importantly, they are adapted for detecting movement.

Answer 25

True

Question 26

Most of the water and salts present in the digestive tract of an insect are absorbed from the digestive tract through the midgut.

Answer 26

False

Question 27

Recent reevaluations of arthropod phylogeny suggest that the subphylum Crustacea may be a paraphyletic group.

Answer 27

True

Question 28

Because insects are vectors for diseases that affect humans; their economic cost to humans far outweighs their beneficial effects.

Answer 28

False

Question 29

Virtually all zoologists agree that the phylum Arthropoda is a monophyletic grouping.

Answer 29

True

Question 30

The first insects likely arose around 35 million years ago.

Answer 30

False