Question

Section 7-Arthropods 

a What do all arthropods have to do periodically, as they get bigger? 

b. Why do arthropods have to do this? (The answer is NOT to get bigger.) 

c. Look at the photo of the preserved arthropod on the right

 1. How many major body regions does it have?

 2. How many legs does it have? 

d. Look at the photo of the crab below. Notice its similarity to the insect, with respect to its tough Jouter exoskeleton, and the way its limbs are put together. How many legs does it have? 

e. Do arthropods have a coelom? 

f. Are arthropods segmented? 

Section 8-Echinoderms 

a. The remains of echinoderms are called tests. They are essentially skeletons. Do echinoderms have an exoskeleton or an endoskeleton?

Answer 1

a) all arthropods have to go through a process known as 'molting'. In this process they shed their outer skeleton (exoskeleton) completely.

b) they do this because they need a new exoskeleton that acts as a barrier and help them to become strong.

c) picture not given

d) picture not given

e) yes all arthropods have coelem.

f) yes all arthropods are segmented.

ECHINODERMS

a) they have endoskeleton.