2.4 Metabolism in Conformers and Regulators

Question 1

State some external abiotic factors that can affect an organism’s ability to maintain its metabolic rate?

Answer 1

Salinity, Temperature and pH

Question 2

What is the definition of a ‘conformer’

Answer 2

An organism whose internal environment is dependent upon external environment

Question 3

What is a ‘regulator’?

Answer 3

An organism that maintains a constant internal body environment regardless of external environment.

Question 4

Give an advantage and a disadvantage of a conformer

Answer 4

:) Low metabolic cost, energy conservation

:( Narrow range of ecological niches, less adaptable

Question 5

Describe the metabolic costs and ecological niches of a regulator

Answer 5

:) Occupy a wide range of niches

:( Energy costs and metabolic costs are high

Question 6

What is ‘Homeostasis’

Answer 6

A process by which a regulator maintains a constant internal body environment regardless of external environment

Question 7

What control mechanism does homeostasis use?

Answer 7

Negative Feedback Loops

Question 8

Describe the process of negative feedback control

Answer 8

Receptors inside a monitoring centre monitor a factor. If it fluctuates from its set point, nerves/hormone messages are sent to effector organs, which will initiate a corrective mechanism to bring factor back to setpoint.

Question 9

What is Thermoregulation?

Answer 9

A form of homeostasis where the body temperature is maintained at optimum

Question 10

What is the optimum body temperature for a human?

Answer 10

37 degrees celsius

Question 11

What is the temperature monitoring centre in humans?

Answer 11

Hypothalamus

Question 12

What type of message is sent to effector organs in thermoregulation

Answer 12

Electrical impulses travelling along nerves

Question 13

What is the response of the sweat glands if there is a increase is detected in the body temperature?

Answer 13

Sweat glands activated, allowing for heat loss by evaportation

Question 14

What type of heat loss is caused by the sweat glands?

Answer 14

Evaporation

Question 15

What is the response of sweat glands if a decrease is detected in body temperature?

Answer 15

Sweat glands close and less heat is lost by evaporation

Question 16

What is the response of the hair erector muscles if a decrease is detected in body temperature?

Answer 16

They contract, raising the hairs on skin, trapping a layer of warm air, insulating the skin

Question 17

What type of heat loss is found by heat on skin? (hair raising etc)

Answer 17

Radiation

Question 18

Vasoconstriction is a response to _______?

Answer 18

A decrease in body temperature

Question 19

What happens in Vasodilation?

Answer 19

Response to increase in body temperature

• blood vessels expand
• blood vessels move closer to surface

Question 20

What happens in Vasoconstriction?

Answer 20

Response to decrease in body temperature

• blood vessels constrict
• blood vessels move away from surface

Question 21

Why is it important to maintain body temperature?

Answer 21

• Enzymes have an optimum, allowing them to work at best, high metabolic rate
• Temperature affects diffusion rates, faster at warmer temps, contribute to maintenance of high metabolic activity

Question 22

What happens to metabolic rate when the internal temperature of a human decreases?

Answer 22

It decreases as well

Question 23

List the ways in which effectors respond to cold temperatures?

Answer 23

• Skeletal muscle - Start shivering producing heat
• Body hair - hair erector muscles contract raising the hairs on skin, trapping a layer of warm air, insulating the skin
• Sweat glands – Sweating stops
• Skin arterioles – Vasoconstriction, blood is diverted away from the skin’s surface reducing heat loss by radiation.
• Metabolic rate – increased to generate more heat

Question 24

List the ways in which effectors respond to hot temperatures?

Answer 24

• Skeletal muscle - Shivering stops reducing body heat production.
• Body hair - Erector muscles relax causing body hair to lie flat on the skin. This reduces the insulating effect of trapped air.
• Sweat glands – Sweat is released on the skin’s surface. Body heat used to evaporate water in sweat, cooling the skin.
• Skin arterioles – Vasodilation, blood is diverted towards the surface, increasing heat loss by radiation.
• Metabolic rate – Decreases to reduce heat production.