Topic 8

Question 1

To maximize fitness..

Answer 1

an individuals response to these changes must be shorter than a period of change

Question 2

Responses to environmental change fall into 3 categories

Answer 2

• developmental
• acclimatory
• regulatory

Question 3

Development response

Answer 3

individuals alters its development to produce a phenotype most suitable to persistent slow change in environmental conditions

Question 4

European freshwater striders developmental response to environment

Answer 4

eggs hatch, adult lifespan is short, and have 2 morphs long winged and short winged.

Question 5

Long winged european striders

Answer 5

can fly, move if pond dries up. more energy into survival than reproduction

Question 6

Short winged european striders

Answer 6

cannot fly, or move if pond dries up. more energy into reproduction than survival

Question 7

Acclimatory response

Answer 7

changes in response to seasonal variations. (ex: thickening of fur)

Question 8

acclimatory = habituation of..

Answer 8

an organisms physiological response to environmental conditions

Question 9

Acclimation

Answer 9

applied to laboratory

Question 10

Acclimatization

Answer 10

applies to nature. tolerances are not fixed but are preconditioned by recent experience w environmental conditions

Question 11

Insect in acclimatory response

Answer 11

freeze avoidance strategy. as temp drops they convert glycogen reserves to alcohol which depress the freezing point of the body = freeze avoidance

Question 12

Freeze tolerance

Answer 12

wood frog. similar to frost hardening in plants. expels fluid interior of cells and controls the ice nucleation process in ICP. (survive up to -50c)

Question 13

Desiccation tolerance

Answer 13

tardigrades or water bears. allow their tissues to dry up when no available water. revitalized when water is available. but not permanent solution

Question 14

Regulatory response

Answer 14

rapid changes in behaviour or rates of physiological processes (shivering)

Question 15

Conformers

Answer 15

allow internal conditions to follow external changes

Question 16

Regulators

Answer 16

maintain constant internal conditions

Question 17

Homeostasis

Answer 17

Organisms must maintain an equilibrium between their internal and external environments (negative feedback system)

Question 18

Negative feedback system

Answer 18

• mechanism that senses internal conditions
• means of comparing the actual with the desired internal conditions
• apparatus that alters internal condition in preferred direction

Question 19

Poikilothermy (conforming)

Answer 19

cannot maintain constant body temp (varies). amphibians, fish, insects, aquatic organisms. active in narrow range of temp

Question 20

Homeothermy (regulating)

Answer 20

maintain constant body temp. birds and animals (36-41 C) where biochemical processes in cell are efficient. active under varying temp

Question 21

Ectotherms

Answer 21

regulate body temp by gaining heat from external sources (poikilotherm)

Question 22

Advantage and disadvantage of ectotherms

Answer 22

A: energy expenditure can be low
D: growth, reproduction and survival is limited by temp fluctuations

Question 23

Endotherms

Answer 23

regulate body temp by production of heat (metabolism) homeotherm

Question 24

Advantage and disadvantage of endotherms

Answer 24

A: growth, reproduction and survival is not affected by temp
D: energy expenditure must be high to maintain metabolic heat production

Question 25

Heterothermy

Answer 25

both ecto and endothermy , change daily or by seasonal cycle or life stage. most flying insects. high metabolic rates are supported.flight muscles must be between 30-44 C to fly

Question 26

Many flying insects pump abdomens or shiver wings to generate heat means

Answer 26

ENDO thermic not heterothermy

Question 27

Limitations of ectotherms

Answer 27

ectotherms generate heat when active.

Question 28

Every aspect of ecology and behaviour is influenced by..

Answer 28

need to regulate body temp

Question 29

Limitations of endotherms

Answer 29

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

Question 30

Limitations of endotherms short term

Answer 30

by physiological capacity to generate heat

Question 31

Limitations of endotherms long term

Answer 31

by ability to gather food (or energy) to satisfy requirements for
metabolic heat production

Question 32

Animals usually starve to death before they de of

Answer 32

direct causes of cold temps

Question 33

Reduce energetic costs by ..

Answer 33

altering the loss/gain of heat from environment in a number of ways

Question 34

1 energy conservation of endotherms

Answer 34

lower regulated temp of portion of body (ex bird feet and legs: counter current heat exchange. heat is minimized by reducing temp gradient between leg and environment)

Question 35

2 energy conservation of endotherms

Answer 35

Lower the regulated temperature at certain times of the day

Question 36

Torpor

Answer 36

temp reduction in metabolic activity and lowered body temp

Question 37

Hibernation

Answer 37

extended reduction of metabolic activity and low body temp

Question 38

Example of lower the regulated temperature at certain times of the day

Answer 38

hummingbirds, inactive at low temps, 50% less energy consumed, reduces heat loss to environment

Question 39

3 energy conservation of endotherms

Answer 39

become larger.the importance of body size in energy conservation lies in the surface area to volume ratio

Question 40

Allometry

Answer 40

surface area to volume ratio

Question 41

Allometric relationship

Answer 41

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

Question 42

As body size increases..

Answer 42

volume increases faster than SA

Question 43

As body size changes..

Answer 43

SA/V ratio changes

Question 44

As SA/V ratio changes..

Answer 44

heat loss to environmental changes

Question 45

The larger the volume the great the..

Answer 45

total amount of heat required to keep warm but less heat is lost through outer surface of organism

Question 46

Small organisms allometry

Answer 46

high SA/V. require less heat but hard to keep warm

Question 47

Large organisms

Answer 47

low SA/V. require more heat but retained easier

Question 48

Bermanns rule

Answer 48

A broadly distributed group of species tend to be larger in size in colder environments and smaller in warmer environment (white tailed deer)