Topic 8 -Animal Adaptations

Question 1

To maximize fitness an individuals response to these changes must be

Answer 1

Shorter than the period of change

Question 2

Responses to environmental change fall into three categories

Answer 2

Developmental

Acclimatory

regulatory

Question 3

Developmental (years) irreversible

Answer 3

Individual alters its development to reduce a phenotype most suitable to a persistent slow change environmental conditions

Question 4

Acclimatory (days-weeks) reversible

Answer 4

Changes in response to seasonal variations such as thickening of fur for winter

Question 5

Examples of acclimatory change

Answer 5

Habituation of an organisms physiological response to environmental conditions

Insect freeze avoidance strategy convert glycogen reserves to alcohol to Lower freeze point of body

Freeze tolerance and wood frog expels fluid interior of cells and controls the ice nucleation process and intercellular space

Desiccation tolerance tardigrade’s allow their tissues to dry up when there’s no available water

Question 6

regulatory (seconds to minutes) reversible

Answer 6

Rapid changes in behaviour or rates of physiological processes example shivering

Question 7

Conformers

Answer 7

Allow internal conditions to follow external changes

Question 8

Regulators

Answer 8

Maintain constant internal conditions

Question 9

Poikilothermy (conforming)

Answer 9

Cannot maintain a constant body temperature

Most amphibians fish and insects
most aquatic organisms
only active in a narrow range of temperature

Question 10

Homeothermy (regulating)

Answer 10

Maintain constant body temperature

Most birds and mammals 36 to 41°C for which biochemical processes within cells are efficient

Highly active under varying temperatures

Question 11

What are Ectotherm’s

Advantages and disadvantages?

Answer 11

Regulate body temperature by gaining heat from external sources

Advantage: energy expenditure can be low

disadvantage: growth, reproduction and survival is limited by temperature fluctuations active only in a narrow range of temperature

Question 12

What are endotherms

Advantage and disadvantages?

Answer 12

Regulate body temperature by the production of heat using metabolism

Advantage: growth, reproduction and survival is not affected by temperature fluctuations. Constant performance of biochemical reactions at a range of environmental temperatures

Disadvantage: energy expenditure must be high to maintain metabolic heat production

Question 13

Limitations of ectotherm’s

Answer 13

Must behaviourally generate heat

Generate heat when active

Question 14

Limitations of endotherm’s

Answer 14

Endotherm’s ability to maintain constant body temperature is limited under low temperatures

Short-term: By physiological capacity to generate heat
Long-term: By ability to gather food or energy to satisfy requirements for metabolic heat production

Question 15

Body size dictates

Answer 15

The morphology, ecology, physiology and evolution of an organism

The importance of body sizing energy conservation lies in the surface area to volume ratio

Question 16

Allometric relationship

Answer 16

A relative increase in a physical or physiological property of an organism in relation to its body size

Question 17

Small organisms

Answer 17

High SA/V

Require less heat but hard to keep warm

Question 18

Large organisms

Answer 18

Low SA/V

Require more heat but it’s retained easier

Question 19

Bergmann’s rule

Answer 19

A broadly distributed group of species tend to be larger in size in cold environments and smaller in warmer environments