Practice questions

Question 1

What are the pharyngeal jaws? Briefly describe one example.

Answer 1

• Secondary set of jaws, used for processign food.
• Modified gill / bracheal arches.
• Can be hard for processing food / sharp for ripping etc.
• e.g. Moray eels - protrude pharyngeal jaws to captire prey.

Question 2

Using diagrams, show the main patterns of skull fenestration shown in the amniotes and give an example for each.

Answer 2

• Anapsid (No hole / fenestra )
• Synapsid (1 hole / fenestra)
• Diapsid (2 holes / fenestra)
• Anapsid e.g. turtle (actually diapsid)
• Synapsid e.g. mammals
• Diapsid e.g. crocodilian

Question 3

Other than the amniotic egg, what are the other derived features of the amniotes?

Answer 3

• Presence of keratin the skin
• Well developed muscles in the throat region
• Fenestration of the skull
• Costal respiration (use ribs for ventilation.
• Thicker skin with more lipids (no gaseous exchange over skin)

Question 4

How do cartilaginous fishes sense their prey?

Answer 4

• Mechanoreception. lateral line that detects vibrations in water.
• Olfaction. Nostrils to sense smell.
• Olfaction can be very sensitive.
• Electroreception that pick up electric signals given off by the movement of prey - nerve, muscles movement. (ampullary organs)
• Specialised modified eyes for low light condition.

Question 5

What are the key features of the mammals?

Answer 5

• Larger brains
• mammary glands
• presence of hair/fur
• endotherms
• lactation & suckling
• diaphragm
• heterodont, jaw
• precise inclusion
• lower jaw is slightly smaller so it can move side to side for chewing

Question 6

Discuss the role of biotic and abiotic factors, specifically predation, in driving the diversity of reproductive modes in anurans.

Answer 6

• Move away from aquatic environment to lower risk of predation
• More complexity of reproductive modes in warmer wetter environments
• e.g. foam nests, terrestrial eggs etc.

Question 7

Illustrate convergent evolution in marsupial and placental mammals

Answer 7

• Gliding evloved independently in both
• Marsupial moles / normal moles
• Diet specialisation
• habitats, body size and morphology