Name _____________________________

1

Z361 Midterm II

Fall 2000

260 points total.

This is a longer exam than last time.

Budget your time carefully!

Name _____________________________

2

1. Fill in the blanks below by choosing a term from the list provided. Each term can only be used once. There are more terms than answers. 45 points. (9 minutes) Branchial Calcium carbonate Cephalopods Chitin Cloaca Closed Cuverian tubules Elongation Epicuticle

Epitokes Foot Gastropods Hirudin Leeches Mantle cavity Metamerism Open Polychaetes

Procuticle Respiratory tree Sodium phosphate Systemic Tagmatization Tentacles Torsion

Many ______________________ undergo a morphological transformation to produce sexually reproductive ________________________. These body forms are highly motile and release large quantities of gametes. ________________________ undergo __________________________ whereby, during the larval stage, the body twists back on itself 180°. The end result is that the _______________________ is positioned over the head of the organism instead of in the posterior of the body. Annelids are characterized as possessing many repeating segments along the anterior-posterior axis. They are said to exhibit a high degree of ________________________. Arthropods also have many repeating segments but these segments are often fused together and modified. This concept of fused segments is known as _________________________. Cephalopods have a(n) __________________ circulatory system that includes two ___________________ hearts that serve the gills and one __________________ heart that serves the rest of the body. The major component of the arthropod exoskeleton is ____________________, an aminated polysaccharide, which is found in the ________________________ layer. Crustacean exoskeletons also contain ______________________ which strengthens the structure. Holothuroids have a unique gas exchange structure called the ____________________. It is irrigated by repeated contractions of the _____________________.

Name _____________________________

3

Name _____________________________

4

Name _____________________________

5

Name _____________________________

6

Question 3 50 points (9 minutes) 3a. List two functions of the water vascular system in echinoderms. __________________________________ ___________________________________ 3b. Which function is considered to be “ancient” or “primitive” compared to the other? 3c. Diagram and label an asteroid water vascular system below. 3d. Describe the water flow through the system from the outside of the animal to the

tube feet. How is flow maintained?

Name _____________________________

7

4. Compare and contrast food acquisition in the protobranch and the lammellibranch

bivalves. Be specific about what structures are involved. 27 points (5 minutes) 5. Compare and contrast burrowing and errant polychaete locomotion. Be specific about

what structures are involved. 28 points. (5 minutes)

Name _____________________________

8

Question 6. 40 points. (8 minutes) 6a. Describe food acquisition and digestion in the hypothetical ancestral mollusc

(HAM). 6b. What is another name for the coelom in HAM? ____________________________ 6c. Where are the gonads located in HAM? 6d. How do gametes end up on the outside of the HAM body?