Topic 7 - Energy Budgets

Question 1

What do organisms need energy for

Answer 1

Maintenance, rapid growth, reproduction, thermo-regulation

Question 2

What factors do energy budgets depend on?

Answer 2

Size
Environment
Thermoregulation

Question 3

How do energy demands differ between larger and smaller body mass

Answer 3

larger body mass needs more energy, but based on body mass, smaller organisms need more

Question 4

How does body size influence energy demand

what behaviours are impacted

Answer 4

impacts how organisms move, how often they eat, what they eat

Question 5

what is the SA to V ratio for smaller organisms compared to larger

Answer 5

smaller organisms have a higher ratio

Question 6

does surface area scale with mass

Answer 6

yes because mass and volume are related

as mass increases, surface area increases

Question 7

why is body size scaling important

explain for volume and more SA

Answer 7

organisms need to obtain resources and excrete waste to support their mass/volume

they exchange matter and generate energy across their membranes (SA)

Question 8

what are the disadvantages of Large organisms with respect to SA:V ratio

Answer 8

reduced efficiency, longer diffusion distance, need for specialized system

lots of biomass needs to be maintained but there is limited SA, stuff needs to flow a long way from in to out, energy must be diverted to build and maintain systems to increase SA

Question 9

what are the advantages of Large organisms with respect to SA:V ratio

Answer 9

Heat retention - heat is produced by entire volume but lost through minimal surface
Water conservation
Structural strength

Question 10

Allometry

Answer 10

when biological phenomena do not vary linearly with body size

Question 11

What are the reasons for allometry

Answer 11

need for structural support and how it changes with size - elephants need thicker bones to hande larger mass

Question 12

Isometry

Answer 12

linear relationship between mass and a biological variable

Question 13

Positive allometry (hyperallometry)

Answer 13

as one dimension increases, the other increases at a faster rate

Question 14

Negative allometry (hypoallometry)

Answer 14

as one dimension increases the other increases at a slower rate

Question 15

How does body size affect energy in

Answer 15

larger animals need more food, greater Ein per unit time, they eat less relative to body size,
they take in more air and pump more blood with each heartbeat - slower breathing and heart rate

Question 16

why do larger animals eat less food per body weight

what characteristic differs between larger and smaller animals

Answer 16

smaller animals have higher metabolic rate so they eat more than their body weight

Question 17

What are strategies to minimize energy lost through excretion (aka how do we increase assimilation)

Answer 17

chewing, selection of palatable foods, gut length, food retention time

Question 18

What is MR

Answer 18

rate of energy consumption - rate at which chemical energy is converted to heat and work

Question 19

RMR

Answer 19

energy expenditure at rest but routine activities

Question 20

BMR

Answer 20

basal, metabolism at complete rest, lowest possible

Question 21

SMR

Answer 21

standard

measured at specified temperature (ectotherms)

Question 22

FMR

Answer 22

field, measured in wild animals

Question 23

what is BMR used for

Answer 23

endotherms

metabolic rate while in TNZ

Question 24

what is SMR used for

Answer 24

ectotherms when fasting/resting

Question 25

Direct calorimetry

Answer 25

measures the rate at which heat leaves an animals body

EXPENSIVE AND CUMBERSOME

Question 26

indirect calorimetry

Answer 26

measures respiration rate

Question 27

what does Eactivity include

Answer 27

most forms of movement above resting state

activity increases heat generated, may offset the thermoregulation costs of a dormant organism

Question 28

what does Eproduction include

Answer 28

growth and reproduction - usually 0, if there is extra energy mass will increase