Reptiles 1

Question 1

Describe reproduction in reptiles.

Answer 1

• Internal fertilisation - males have copulatory organ

* Most species are oviparous but others are ovoviviparous and viviparous.

Question 2

Define partenogenesis.

Answer 2

Complete absence of male contributions - no sexual reproduction.

Question 3

Describe temperature dependent sex determination in amphibians.

Answer 3

• Widespread in turtles, crocodilians and lizards
• Temperature of nest affects rate of embryonic development
• Mothers can choose sex of offspring via basking behaviour.

Question 4

Describe reptilian lungs.

Answer 4

• More developed than amphibian lungs
• Divided into chambers and sub-chambers (faveoli)
• Increases surface area for gas exchange

Question 5

What gas exchange methods do reptiles use?

Answer 5

• Primarily depend on lungs
• Some gas exchange takes place inside mouth and in the cloaca (particularly in turtles)
• Up to 70% of gas exchange takes place on skin covering shell of soft shelled turtles.

Question 6

Describe hearing in reptiles.

Answer 6

• Low frequencies and vibration

* Some have external ear structures .

Question 7

Describe thermoregulation in reptiles.

Answer 7

(Ectotherms)
•Morphology: skin colouration
•Behaviour: basking
•Physiology: heart rates.

Question 8

What are the differences between reptiles and amphibians?

Answer 8

• Reptilian skin is dry and scaly
• Amniotic egg: allow embryo to bypass aquatic stage of amphibians
• Reptilian jaws are more powerful and skull openings allow more surface area for muscle attachment allowing greater pressure to be exerted.
• Limbs are more parallel to body in reptiles.

Question 9

What are the sex chromosomes for reptiles?

Answer 9

XY/XX = Male/Female
(Most reptiles)

WZ/WW = Female/Male
(Few reptiles).

Question 10

Describe snake lungs.

Answer 10

Single dominant left lung.

Question 11

What direction does air flow within reptiles?

Answer 11

• Most are bidirectional

* Some reptiles are unidirectional including alligators.

Question 12

Describe reptilian vision.

Answer 12

Active during day:
•complex eyes (rods & oil droplets)
•See colour well

Active at night:
•lizards - large pupillary and lens aperture
•Some snakes - infrared vision (pit organ).

Question 13

Describe reptilian sense of smell.

Answer 13

Possess Jacobson’s organ inside mouth for detention of chemicals via the tongue.

Question 14

Describe thermoregulation adaptions in reptiles.

Answer 14

(Ectotherms)
•Morphology - skin colouration
•Behaviour - basking
•Physiology - heart rates.