Lecture Fifteen - Animal adaptations I

Question 1

What are some animal responses to changes in the environment?

Answer 1

Avoidance = space and time.

Conformaluty or tolerance = undergoes internal change similar to external.

Regulation = maintain internal despite changes in external.

Question 2

What are the mechanisms of homeostasis?

Answer 2

Moderate changes in the internal environment.

Receptor - detects change.

Control centre - processes incoming information and directs response.

Effector - effects response.

Thermoregulation = processes to maintain an internal temperature within a tolerable limit.

Question 3

What are ectotherms and endotherms?

Answer 3

Ectotherms - Low metabolic rate, gain most of heat from environment. Mainly behavioural but commonly can tolerate greater variation.

Endotherms - High metabolic rate, can use heat to regulate body temperature.

Question 4

How can animals balance heat loss and gain?

Answer 4

Heat gain/maintenance:

Insulation:

Feathers, hair = trap air, efficiency depends on how much still air is trapped.

Fat.

Blubber - transfer of heat is 50-100 times faster in water, therefore water dwellers general have lots of blubber.

Vasodilation and vasoconstriction.

Counter current heat exchange - transfer of heat to fluid flowing in opposite direction.

Sun bathing.

Heat loss:

Bathing, panting, sweating, saliva on body surface.

Question 5

What are the three biogeographical areas in Australia?

Answer 5

Question 6

Describe frogs in arid conditions.

Answer 6

Escape the arid conditions.

Many burrow (fossorial).

Make cocoon.

Reduce metabolism so can survive five years underground - similar periodicity to El Nino.