Lecture 10

Question 1

What is a morphological result of light travelling better in air than water, with less disturbance?

Answer 1

Tetrapods have flatter corneas than fishes do

Question 2

What is the difference between fishes and tetrapods in regards to lenses?

Answer 2

Fishes move their lenses whereas tetrapods change the shape of the lens along with developed lubrication

Question 3

Describe the transmission of sound from tympanum to optic capsule

Answer 3

Receives waves on tympanum/eardrum, transmitted by

middle ear bones to oval window of otic capsule.

Question 4

Describe the transmission of sound from oval window to stimulation

Answer 4

Oval window compression compresses inner ear fluids, stimulating hair cells in organ of Corti.

Question 5

What structure connects the mouth with the inner ear?

Answer 5

The eustachian tube

Question 6

What was the eustachian tube derived from?

Answer 6

The spiracles

Question 7

How many times did the middle ear evolve convergently and what remained the same?

Answer 7

At least five times in tetrapods. Stapes always transmitted vibrations

Question 8

What increases surface area in olfactory receptors?

Answer 8

Nasal turbinates

Question 9

What is the action of curling back of the lip called and what does it do?

Answer 9

Flehmen, passes scents over vomeronasal organ

Question 10

What provides the most protection against water loss?

Answer 10

Lipid layers: Keratin to form stratum corneum

Question 11

What is the process that is a new feature of tetrapods?

Answer 11

Urinary bladder receiving urine from kidney and voiding it to outside

Question 12

What is the path of urine in tetrapods?

Answer 12

Kidney, bladder then cloaca

Question 13

What are the 6 different ways of heat exchange?

Answer 13

Solar & infrared radiation, convection, conductive heat exchange, evaporation & metabolic heat production

Question 14

Describe some ways that lizards cope with heat exchange

Answer 14

They lift themselves up to increase surface area (stilting) and change their colour, dark to keep heat and light to reflect heat

Question 15

What is the themophilic effect?

Answer 15

When animals have eaten, their temperature increases to aid in digestion

Question 16

Give an example of when temperature changes during pregnancy

Answer 16

Female lizards will lower their temperature to balance needs between adult and young

Question 17

Describe behavioural fever

Answer 17

There’s a change in thermoregulatory behaviour and increased temperature when infected with bacteria resulting in a decrease of bacterial growth

Question 18

What is a draw back and a result of being a small endotherm?

Answer 18

Energy costs are very high for small endotherms, therefore they tend to not be as small as amphibians & reptiles

Question 19

What can ectotherms do in regards to energy?

Answer 19

They can convert a higher amount of their energy intake into biomass & maintain themselves on lower energy intakes

Question 20

How is free water (in desert conditions) absorbed?

Answer 20

Water content of food, absorbed across wall of intestine

Question 21

Describe metabolic water

Answer 21

By-product of metabolism as protons combine with oxygen. Volume produced depends on food source

Question 22

What are the routes of water loss?

Answer 22

Evaporation, urine & faeces and salt glands

Question 23

Name the long-term ways of retaining water

Answer 23

• reduction in water loss rates through skin
• tolerance of elevated solutes
• delayed salt excretion
• urine as water reserve