ECOL 182R - MIDTERM 3 UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

ECOL 182R - MIDTERM 3 UPDATED ACTUAL QUESTIONS
AND CORRECT ANSWERS

Question:
1. What are five characteristics of all animals?
Answer:
-Multicellular
-Heterotrophic
-No cell wall, instead Extracellular Matrix (ECM)
-Self-propelled movement
-Have neurons and muscle cells

Question:
2. What characteristics do sponges not have?
Answer:
Neurons and muscle cells.

Question:
3. What is the ECM and what does it provide for the animal?
Answer:
-ECM = Extracellular Matrix is a large network of proteins and carbohydrates secreted by animal/fungal
cells
-ECM provides mechanical protection and structural support

Question:
4. What is the name of the clade that encompasses both Lophotrochozoans and Ecdysozoans?
Answer:
Protostomes.

Question:
5. How do Lophotrochozoans grow?
Answer:
Grow incrementally by adding to their structural elements.

Question:
6. How do Ecdysozoans grow?
Answer:
Grow by molting.

Question:
7. What is a distinguishing feature of Deuterostomes?
Answer:
-Have endoskeletons (internal skeletons)
-Not all are vertebrates

, Question:
8. What happens to the blastopore in development of protostomes?
Answer:
Blastopore gives rise to the mouth.

Question:
9. What happens to the blastopore in development of Deuterostomes?
Answer:
Blastopore gives rise to the anus.

Question:
10. How do Porifera exhibit movement?
Answer:
Self-propelled movement; sink their spicules into the ground and pull on them to haul their bodies forward.

Question:
11. What are the four ways that Porifera are different from other animals?
Answer:
-Sponges lack neurons and muscle cells
-Sponges lack tissues; have cellular organization
-Sponges lack symmetry (asymmetrical)
-Sponges lack a mouth (pores draw in food/water)

Question:
12. What are the three types of symmetry?
Answer:
-Asymmetry (sponges)
-Radial Symmetry (Cnidaria - jellyfish, anemones, coral, etc.)
-Bilateral Symmetry (humans, cats, etc.)

Question:
13. What are the advantages of bilateral symmetry?
Answer:
-Allows concentration of sensory organs on one side (the front) of one end (the top)
-Usually associated with a central nervous system (and a brain)
-Good thing for mobile animals because it aids in quick responses and moving in a forward direction

Question:
14. Where/when do radial and bilateral symmetry occur on the phylogenetic tree of animals?
Answer:
-Radial symmetry occurs after the first branching out of the common ancestor of all animals, but before the
ancestor of Cnidaria
-Bilateral symmetry occurs before the branching of protostomes and deuterostomes