Chapter four: Coping with Variation

Question 1

Why do organisms occur where they do?

Answer 1

Ultimately determined by a physical environment and interactions with other species.

Question 2

What is a climate envelope?

Answer 2

A range of conditions over which a species occurs; can predict response to climate change.

Question 3

What are organisms two options for coping with environmental variation?

Answer 3

Tolerance and avoidance.

Question 4

What is physiological ecology?

Answer 4

The study of interactions between organisms and their environment and how these interactions influence survival and determine geographic ranges.

Question 5

How does the physical environment influence an organisms ecological success?

Answer 5

Through availability of energy and resources. And whether extreme conditions can exceed tolerance limits.

Question 6

What other factors are related to geographic distribution?

Answer 6

Dispersal ability, disturbance, and competition.

Question 7

Explain the range of tolerance.

Answer 7

The range of environmental changes within which a species is able to carry out normal activities. If the upper or lower limit exceeds the range of tolerance, efficiency is effected.

Question 8

What is “stress”?

Answer 8

Environmental change results in decreased rates of survival, growth, or reproduction.

Question 9

What is the principal of allocation?

Answer 9

When stressed, more energy must be devoted to basal metabolism, thus less energy is available for survival. (Energy=finite)

Question 10

What is acclimization?

Answer 10

Adjusting to stress through behavior or physiology. (Short term).

Question 11

What is adaptation?

Answer 11

Natural selection facilitates adaptation to environmental stress in a population (Long term).

Question 12

What are ecotypes?

Answer 12

Populations with adaptations to unique environments.

Question 13

What is survival and function strongly tied to?

Answer 13

Internal temperature.

Question 14

What are isozymes?

Answer 14

Different forms of enzymes with different temperature optimum. They allow for acclimatization to changing conditions.

Question 15

What is an ectotherm?

Answer 15

Principal source of heat comes from outside the body.
Ex: Reptiles

Question 16

What is an endotherm?

Answer 16

Can maintain constant body temperature by heat produced inside the body.
Ex: Mammals

Question 17

What is a homeotherm?

Answer 17

The constant body temperature comes by physiological means, like metabolism.

Question 18

What is a heterotherm?

Answer 18

Has multiple set points of temperature.
-Regional: body temperature varies on different parts of the body.
-Temporal: body temperature varies at different times.

Question 19

What are poikilotherms?

Answer 19

Variation in body temperature under different environmental conditions.

Question 20

What must organisms do to tolerate, change, or modify temperature?

Answer 20

Use physiology, morphology, or behavior behaviors.

Question 21

Define conduction.

Answer 21

The transfer of energy from warmer to cooler molecules (surface contact).

Question 22

Define convection.

Answer 22

Heat energy is carried by moving water or air. Ex: wind or bounced surfaces.

Question 23

Define radiation.

Answer 23

Energy from the sun.

Question 24

Define latent heat transfer.

Answer 24

Water absorbs heat as it changes from a liquid to a gas.

Question 25

What are the 3 ways ectotherms gain heat?

Answer 25

Radiation, convection, and conduction.

Question 26

What are 3 ways ectotherms lose heat?

Answer 26

Convection, respiration, and conduction.

Question 27

What are the energy inputs for terrestrial plants?

Answer 27

Sunlight, infrared radiation from surrounding objects, conduction, and convection if the ground or air is warmer than the plant.

Question 28

What are the energy outputs for terrestrial plants?

Answer 28

Emission of infrared radiation, conduction, convection, and evapotanspiration.

Question 29

What controls transpiration in plants?

Answer 29

Stomata, tiny and specialized leaf openings.

Question 30

If soil water is limited, what are the ways plants can conserve energy/water.

Answer 30

By shedding leaves and pubescence (hairs on a leaf that reflect solar energy)

Question 31

Define the thermal neutral zone.

Answer 31

Endotherms maintain constant basal metabolism over a range of environmental temperatures.

Question 32

Define basal metabolic rate.

Answer 32

The amount of oxygen consumed per time unit at a standard temperature.
And the amount of energy spent at rest.

Question 33

Define relative or mass-specific metabolic rate.

Answer 33

Meaning metabolic rate is adjusted for body size.
As body size increases, relative BMR decreases.
(Large endotherms lose energy/heat more slowly.)

Question 34

Name the behavioral adjustments for a lower critical temperature.

Answer 34

Huddling, piloerection (hair stands up), elaborate nests, restricting foraging areas, food hoarding, and restricting level of activity.

Question 35

Name the morphological adjustments for a lower critical temperature.

Answer 35

Bergman’s rule (body size increases with latitude.)
Allen’s rule (colder climates results in shorter appendages.)
Gloger’s rule (drier climates results in lighter pigment)

Question 36

Name the physiological adjustments for a lower critical temperature.

Answer 36

Insulation with fur/feathers.
Countercurrent heat exchange (changes in blood flow to peripheral tissues)
Dormancy (torpor, hibernation, and winter lethargy)
Thermogenesis (Shivering v.s. nonshivering)

Question 37

Name the behavioral adjustments to a upper critical temperature.

Answer 37

Burrowing, denning, fanning.
Shading with appendages
Diet, including more water.
Restrict level of activity.

Question 38

Name the morphological adjustments to a upper critical temperature.

Answer 38

Decreased body size (Bergman’s rule)
Longer appendages (Allen’s rule)
Darker skin pigment (Gloger’s rule)

Question 39

Name the physiological adjustments to a upper critical temperature.

Answer 39

Evaporative cooling (sweating, panting, salvia spreading, respiratory heat exchange.)
Dormancy