Energy Budgets

Question 1

What is the principal of energy budgets?

Answer 1

Organisms have similar energy demands but may differ on the amount they spend on each part of their life history

Question 2

Describe energy needs for larger and smaller animals.

Answer 2

Larger organisms require more energy in total, but smaller organisms require more energy per unit body mass (they have a higher metabolic rate)

Question 3

What happens what there is more membrane/skin? What happens when there is more mass?

Answer 3

More membrane/skin means more surface area. More mass means more volume

Question 4

What is energyRMR?

Answer 4

Resting metabolic rate

Question 5

What is energyActivity?

Answer 5

Behaviour, reproduction, thermoregulation, etc…

Question 6

What is energyProduction?

Answer 6

Stored by the organism

Question 7

What is energyExcretion?

Answer 7

What gets lost by the organism to the environment

Question 8

What are some characteristics of larger animals?

Answer 8

• Need more ENERGYin per unit time
• Can eat more food (eat less relative to body size)
• Take in more air with each breath and pump more blood with each heartbeat (slower breathing and heart rate)

Question 9

What happens if Eproduction is positive? What happens if it is negative?

Answer 9

If Eproduction is positive there will be a gain of mass.
If Eproduction is negative there will be a loss of mass

Question 10

What influences energy budgets?

Answer 10

• Thermoregulation: ectotherms require less energy than endotherms
• Environment: the environment you live in will affect energy needs

Question 11

What is scaling?

Answer 11

How size (or mass) affects the anatomy, physiology, and biological processes

Question 12

What does scaling influence?

Answer 12

• The way an organism moves
• How often they eat
• What they eat

Question 13

What does scaling up mean?

Answer 13

A lot more surface area and even more volume.
Volume = l x w x h (a proportion cubed)

Question 14

What is the ratio for surface area and volume for larger organisms?

Answer 14

Larger organisms have smaller surface area to volume ratios

Question 15

Why have larger organisms evolved ways to increase surface area?

Answer 15

To exchange matter and energy with their environment

Question 16

Does surface area scale with mass?

Answer 16

Yes, because mass and volume are related

Question 17

How do organisms support their mass (volume)?

Answer 17

Obtain resources and excrete waste

Question 18

How do organisms generate energy across their membrane (surface area)?

Answer 18

Exchange matter

Question 19

What are disadvantages to large organisms in relation to their surface area and volume ratio?

Answer 19

• Reduced efficiency: lots of biomass needs to be surfaced but little surface area to do it with
• Diffusion distance: “stuff” needs to flow a long way from inside to outside
• Specialized systems: need to divert energy to building and maintaining systems to increase surface area

Question 20

What are advantaged to large organisms in relation to their surface area and volume ratio?

Answer 20

• Heat retention: heat is produced by the entire volume, but lost through much less surface
• Water conservation
• Structural strength

Question 21

Explain the allometry formula.

Answer 21

Isometric is a linear graph, allometric is a non-linear graph.
b = 1 is isometric
b = 0 is independant of mass
b = anything else is allometric

Question 22

What is allometry?

Answer 22

Many biological phenomena do not vary linearly with body size. Allometry is needed for structural support and how it changes with size is an example

Question 23

What is positive allometry?

Answer 23

As one dimension increase, the other increases at a faster rate

Question 24

What is negative allometry?

Answer 24

As one dimension increases, the other increases at a slower rate

Question 25

What are some ways to minimize Energyexcretion?

Answer 25

Chewing, selecting more palatable foods, length of gut, food retention time

Question 26

What does food quality affect?

Answer 26

Food quality affects retention time. Some animals can change their gut size depending on the season (this is a type of plasticity)

Question 27

What is metabolic rate (energyRMR)?

Answer 27

Rate (in unit of time) an organism converts chemical energy into heat and external work. It is the rate of energy consumption.

Question 28

Why does metabolic rate matter?

Answer 28

• Helps determine how much food an animal needs
• Quantitative measurements of energy expenditure of all physiological mechanisms
• Helps determine the pressure on energy supplies in an ecosystem

Question 29

What are the different types of metabolic rates?

Answer 29

• Resting metabolic rate: energy expenditure at rest but still doing daily activities
• Basal metabolic rate: energy expenditure at complete rest, lowest possible (endotherms)
• Standard metabolic rate: metabolic rate measured at a specific temperature (ectotherms)
• Field metabolic rate: metabolic rate measured in wild animals

Question 30

Describe basal metabolic rate for ectotherms.

Answer 30

Metabolic rate while it is in the thermoneutral zone, fasting, resting

Question 31

Describe standard metabolic rate for endotherms.

Answer 31

Metabolic rate while it is fasting or resting but specific to the prevailing body temperature