Water and Temperature Regulation

Question 1

What is the theory of tolerance?

Answer 1

There is a zone of tolerance where an organism is capable of surviving, an optimal zone where it is capable of reproducing. Outside the tolerance zone is death

Question 2

How do animals gain and lose water?

Answer 2

Gain mostly by drinking and eating. Can absorb through the skin, but some organisms are better than others at this. Lose by evaporation and in secretions

Question 3

How do plants gain and lose water?

Answer 3

Gain by absorbing through the roots and from moist air. Lose from evapotranspiration.

Question 4

How do plants regulate water in a dry environment?

Answer 4

Roots are deeper with more hairs, most biomass is below the ground.

Question 5

How do plants prevent water loss? 6 ways

Answer 5

1. open the stomata when it’s cooler
2. reduced leaf area compared with root area
3. thick leaves with very few stomata
4. periodic dormancy
5. wilting leaves
6. cuticle

Question 6

How do animals prevent water loss? 8 ways

Answer 6

1. raise body temperature
2. reduce metabolic rate
3. have a more efficient large intestine to reabsorb water
4. enlarged nasal passages that condense leaving water vapour
5. Water-proof skin, fur, feathers, scales
6. Be active when it’s cooler
7. burrows and microclimates
8. migrate

Question 7

How do animals regulate their salt balance?

Answer 7

1. get more by licking salt, eating plants high in salt
2. eliminate excess salts through urine or drink more water
3. Concentrate urine
4. Salt glands in marine species (modified tear glands)

Question 8

What is an energy budget?

Answer 8

Describes how an organisms allocates energy to essential life activities -> growth, reproduction, activity, and maintenance. All can’t be simultaneously maximized if energy supplies are limited, have to compromise

Question 9

Why does adapting to one environment reduce fitness in another?

Answer 9

A trait can be beneficial in one environment and detrimental in another

Question 10

What is the law of toleration?

Answer 10

Distribution and abundance of a species depends on the deviation between local conditions and the optimal conditions of a species

Question 11

How does temperature affect animal performance?

Answer 11

Driven by effect on enzyme function. Optimal temperature is usually an intermediate temperature that allows fast functioning and some shape flexibility

Question 12

What are 4 ways animals regulate their temperature?

Answer 12

1. Body size
2. body shape
3. pigmentation
4. activity (behaviour)

Question 13

What is an ectotherm?

Answer 13

Most heat comes from external sources

Question 14

What is an endotherm?

Answer 14

Most heat comes from metabolism

Question 15

What is a poikilotherm?

Answer 15

Body temperature changes directly with the environment temperature

Question 16

What is a homeotherm?

Answer 16

Maintains a relatively constant internal environment

Question 17

What kinds of animals are endotherms?

Answer 17

Birds and mammals

Question 18

How do animals conserve heat? 4 ways

Answer 18

1. reduce evaporation by ceasing to sweat, or by having scales, fur, or feathers
2. Hibernation or torpor
3. Change activity levels
4. Reduce convection and/or conduction
5. Lower surface area: volume ratio (larger body)

Question 19

How are plants different from animals in terms of how heat is lost and gained?

Answer 19

Not much heat is generated through metabolic functioning, not much heat is lost through evaporation

Question 20

How do plants gain and lose heat through conduction and convection?

Answer 20

Conduction: gained through the roots, colour of the ground
Convection: long stems and open leaves increases heat gain and loss from the wind

Question 21

How does altitude, aspect, vegetation, and ground colour and structure affect how a plant regulates its temperature?

Answer 21

The microclimate
Lower temperatures at higher altitudes, whether facing north or south affects the amount of sun exposure and water loss, stratification of plant layers, dark ground absorbs more heat, structure of surface can provide heating and sheltering

Question 22

How do arctic and alpine plants minimize heat loss?

Answer 22

Dark leaves, plant is squat and close to the ground to stop cooling from convection, leaves perpendicular to the sunlight, flowers are white and shaped to project sunlight on the reproductive organs

Question 23

How do desert plants decrease heat storage?

Answer 23

Stems and leaves open to cool from convection, light coloured leaves, leaves parallel to sunlight, white flowers, can have reflective hairs on the leaves, small leaves

Question 24

How do understory plants maximize the amount of light received?

Answer 24

Dark, broad leaves that capture any light that reaches the forest floor