Arthropod Overview

Question 1

Which two spiders that occur in the Sonoran Desert region are medically important, meaning their bite might cause a trip to the emergency room?

Answer 1

Arizona brown spider and black widow.

Question 2

How long ago did arthopods first evolve?

Answer 2

At least 600 million years ago.

Question 3

The periods between molts are called instars.

True or False

Answer 3

True

Question 4

The exoskeleton is made of chitin.

True or False

Answer 4

True

Question 5

The name arthopod comes from the Greek word for “joint” (artho) and “foot” (poda).

True or False

Answer 5

True

Question 6

Arthopods have bones.

True or False

Answer 6

False

Question 7

Most, but not all, arthropods are bilaterally symmetrical.

True or False

Answer 7

True

Question 8

Arthropods account for approximately 85% of all know animal species on earth.

True or False

Answer 8

True

Question 9

In order to grow, an arthropod must shed or molt its exoskeleton and form a new, larger one.

True or False

Answer 9

True

Question 10

Invertebrates represent over 95% of all known animal species.

True or False

Answer 10

True

Question 11

Bark scorpion stings can be dangerous for children.

True or False

Answer 11

True

Question 12

Arthropods have left a very good fossil record.

True or False

Answer 12

False

Question 13

Arthropods were among the earliest animals to evolve.

True or False

Answer 13

True

Question 14

Metemorphosis is the life history that includes a transition in body form, such as a “larval stage” to adult.

True or False

Answer 14

True

Question 15

Check the feature(s) all arthropods share.

___ Paired jointed legs

___ Segmented body

___ Exoskeleton

___ Body hairs

___ Cryptic coloration

Answer 15

_X_ Paired jointed legs

_X_ Segmented body

_X_ Exoskeleton

___ Body hairs

___ Cryptic coloration

Question 16

The arachnids (subphylum Chelicerate, class Arachnida) comprise a diverse and complex group. Spiders, ticks, vinegaroons are all arachnids.

True or False

Answer 16

True

Question 17

Check the reason(s) why arthropods are so diverse (i.e., why has the evolutionary radiation of this group been so spectacular)?

___ They have been around a long time (>500 million years).

___ Huge size range (100 microns to 3 meters).

___ Co-evolution with plants on land, and algae in the sea.

___ Flight.

___ Can occupy diverse niches.

Answer 17

_X_ They have been around a long time (>500 million years).

_X_ Huge size range (100 microns to 3 meters).

_X_ Co-evolution with plants on land, and algae in the sea.

_X__ Flight.

_X_ Can occupy diverse niches.

Question 18

Match the term with the definition.

____ Invertebrate

____ Vertebrate

a. Animal without a backbone
b. Animal with a backbone

Answer 18

____ Invertebrate (a. Animal without a backbone)

____ Vertebrate (b. Animal with a backbone)

Question 19

Match the subphyla (on extinct, four living) with the arthropods that occur in the Sonoaran Desert region.

__ Trilobitea

___ Crustacea

___ Hexapoda/Insecta

___ Myriapoda

___ Chelicerata

a. Centipedes, millipedes, etc.
b. Tarantulas, scorpions, mites, ticks, horseshoe crabs, etc.
c. 4000 species, extinct since the end of the Paleozoic (250mya)
d. Shrimps, crabs, barnacles, etc.
e. ants, silverfish, etc.

Answer 19

_c_ Trilobitea (4000 species, extinct since the end of the Paleozoic (250mya))

_d__ Crustacea (Shrimps, crabs, barnacles, etc.)

_e__ Hexapoda/Insecta (ants, silverfish, etc.)

_a__ Myriapoda (Centipedes, millipedes, etc.​)

_b__ Chelicerata (Tarantulas, scorpions, mites, ticks, horseshoe crabs, etc.)

Question 20

Match the invertebrate to its description.

_____ Centipedes

_____ Millipedes

a. Have one pair of legs/segment and are active predators.
b. Have two pair of legs/segment and are herbivores/detritivores.
c. Cylindral body, cryptic coloration
d. Flat body, aposematic coloration

Answer 20

_a__d__ Centipedes

_b__c__ Millipedes

a. Have one pair of legs/segment and are active predators.
b. Have two pair of legs/segment and are herbivores/detritivores.
c. Cylindral body, cryptic coloration
d. Flat body, aposematic coloration

Question 21

Match the insect metamorphosis to its description.

_____ Hemimetabolous development

_____ Holometabolous development

a. Abrupt post-embryonic changes (=metamorphosis) in body form dramitic (e.g., larvae, pupae, etc.)
b. Gradual post-embryonic change in body form not dramatic.
c. 85%of insects undergo this type of development
d. 15% of insects undergo this type of develpment

Answer 21

_b__d__ Hemimetabolous development

_a__c__ Holometabolous development

a. Abrupt post-embryonic changes (=metamorphosis) in body form dramitic (e.g., larvae, pupae, etc.)
b. Gradual post-embryonic change in body form not dramatic.
c. 85%of insects undergo this type of development
d. 15% of insects undergo this type of develpment