Hexapods

Question 1

What is the insect exoskeleton composed of?

Answer 1

Complex plates (sclerites)

Question 2

Compared to crustaceans, what causes the rigidity of insect exoskeletons? What does this adaptation allow for?

Answer 2

Scleroproteins (not chitin matter)

Question 3

An extension of jointed segments became ___

Answer 3

Appendages

Question 5

What are the benefits of an exoskeleton?

Answer 5

Protection against predators and environmental hazards, provides a secure site for muscle attachments

Question 6

What are the layers of the arthropod cuticle?

Answer 6

Inner thick procuticule, outer thin epicuticle

Both have several layers called lamina

Question 7

What is the epicuticle composed of?

Answer 7

Proteins and lipids

Question 8

In crustaceans and insects, the cuticle forms ingrowths to which muscles are attached for movement. What are these ingrowths?

Answer 8

Apodemes

Question 9

What factor limits the final body size when molting?

Answer 9

Weight

Question 10

What are fused or combined specialized segments called?

Answer 10

Tagmata

Question 11

True or False: Like vertebrates, limbs of arthropods have a skeleton produced by the cuticle where muscles attach to

Answer 11

False, the limb segments of arthropods are hollow and are moved by internal striated muscles

Question 12

What is a benefit of metamorphosis?

Answer 12

Decreased competition among the same species during different parts of their life

Question 13

What are the three distinct regions of trilobites?

Answer 13

Cephalon, trunk, pygidium

Question 14

What are the two tagmata of chelicerates?

Answer 14

Cephalothorax (prosoma) and abdomen (opisthosoma)

Question 15

What are the 6 pairs of chelicerate appendages?

Answer 15

Chelicerae (1st)
Pedipalps (2nd)
Walking legs (4 pairs)

Question 16

True or False: While most chelicerates suck juices from their prey, some can shred their food

Answer 16

True, Order Scorpiones, Order Solpugida, some spiders can crush and chew their prey

Question 17

One defining feature of chelicerates from other arthropods are two things:

Answer 17

Lack of mandibles and antennae

Question 18

Class Merostomata contains what two orders?

Answer 18

Xiphosurida and Eurypterida

Question 19

Unlike most other chelicerates, Class Merostomata were found to have what feature commonly found in insects?

Answer 19

Compound eyes

Question 20

What are the pair of legs of sea spiders that carry developing eggs?

Answer 20

Ovigers

Question 21

What were the first arthropods to move on land?

Answer 21

Arachnids

Scorpions first appeared in the Silurian

Question 22

What are the pedipalps of male arachnids modified for?

Answer 22

Sperm transfer

Question 23

What joins the unsegmented cephalothorax and abdomen of arachnids?

Answer 23

A slender pedicel

Question 24

True or False: Venom glands can be found on the tip of the pedipalps in arachnids

Answer 24

False, they are connected to the terminal fangs of the chelicerae

Question 25

Where is sperm stored among male spiders?

Answer 25

Small web sacs placed within specialized cavities in the pedipalps

Question 26

A male spider inseminates a female spider by: a) normal abdomen to abdomen mating. B) external fertilization where a male spider dances a female over a spermatophore packet. C) injecting sperm with his pedipalps and then rapidly retreating before being eaten. D) transferring sperm via silk. E) avoiding the dangerous female spider altogether and fertilizing the eggs after they are laid in an egg case.

Answer 26

C.

Question 27

True or False: Scorpions are most common in temperate zones

Answer 27

False, they are most common in tropical and subtropical regions

Question 28

How do sand-dwelling scorpions detect movement?

Answer 28

Sensillae on their leg segment

Question 29

The abdomen of scorpions are divided into two:

Answer 29

- Prosoma (pre-abdomen) made of 7 segments - Mesosoma (postabdomen), the long slender tail made of 5 segments that holds the stinger apparatus

Question 30

These are tactile organs used for exploring the ground and sex recognition

Answer 30

Pectines

Question 31

For scorpions, mating is particularly risky for the male since the female can eat the male. Therefore, the male scorpion A) uses the same procedure as male spiders. B) holds the females pincers in a "dance" position, deposits a spermatophore on the ground and dances her over it. C) transfers a spermatophore from between his body segments directly into hers. D) fertilizes her by hypodermic insemination where the sperm is injected inside her body cavity. E) still uses regular mating since this copulatory position keeps her facing away safely.

Answer 31

B, males of some species sting the female on the pedipalp or on the edge of cephalothorax

Question 32

This is an order also called the sun spiders, camel spiders, wind spiders

Answer 32

Order Solpugida

Question 33

This order can lose their legs without much ill effect

Answer 33

Order Opiliones

Question 34

This order has complete fusion of the cephalothorax and abdomen without external segmentation

Answer 34

Order Acari

Question 35

The mouthparts of ticks are located on an anterior projection called the A) prostomium B) peristomium C) capitulum D) rostrum

Question 36

Name some examples of mites

Answer 36

- House dust mites - Spider mites - Chiggers or redbugs

Question 37

These arachnids transmit Asiatic scrub typhus

Answer 37

Redbugs

Question 38

Largest order of arachnids

Answer 38

Order Acari

Question 39

This mite causes mange

Answer 39

Hair follicle mite, *Demodex folliculorum*

Question 40

Human itch mite that causes scabies

Answer 40

*Sarcoptes scabei*