2.4 Criteria

Question 1

What is metabolic rate affected by?

Answer 1

Abiotic factors including temperature, salinity and pH

Question 2

What is the internal environment of conformers dependent upon?

Answer 2

The external environment

Question 3

What responses do conformers use to allow them to tolerate variations in the external environment?

Answer 3

Behavioural responses

Question 4

What is an example of a behavioural response and the conformer that uses it.

Answer 4

Sunbathing in lizards

Question 5

What does behavioural responses allow conformers to maintain?

Answer 5

An optimal metabolic rate

Question 6

Do conformers have high or low metabolic costs?

Answer 6

Low

Question 7

Do conformers have wide or narrow ecological niches?

Answer 7

Narrow

Question 8

Do regulators rely on the external environment to maintain their internal environment?

Answer 8

No (internal environment of regulators is maintained regardless of the external environment).

Question 9

What do regulators use to control their internal environment?

Answer 9

Metabolism

Question 10

What is an example of internal environments controlled by metabolism?

Answer 10

Temperature, water balance, blood sugar.

Question 11

Define Homeostasis:

Answer 11

The use of physiological mechanisms to maintain internal body conditions at optimum levels.

Question 12

What do regulators expend energy on?

Answer 12

To achieve homeostasis

Question 13

Will homeostasis increase or decrease metabolic costs?

Answer 13

Increase

Question 14

Do regulators have a wide or narrow ecological niche?

Answer 14

Wide

Question 15

Define thermoregulation:

Answer 15

The maintenance of a constant internal temperature

Question 16

What is the hypothalamus?

Answer 16

Is the temperature monitoring centre

Question 17

How is information communicated from the hypothalamus to effectors through nerves?

Answer 17

Temperature change is felt by effectors in the skin. Impulses are sent from effectors in skin to hypothalamus in brain. It contains thermoregulators. Impulses are sent back to effectors from the thermoregulators and a change is made.

Question 18

What is negative feedback control?

Answer 18

Negative feedback control uses corrective responses to reverse changes in internal temperature to return temperature to normal (the set point)

Question 19

Explain the human response (sweating) to an increase in body temperature?

Answer 19

Body heat is used to evaporate water in sweat thereby cooling the skin.

Question 20

Explain the human response ( vasodilation) to an increase in body temperature?

Answer 20

Increased blood flow to the skin increases heat loss by radiation.

Question 21

What does a reduction in metabolic rate also reduce?

Answer 21

It reduces heat production

Question 22

Explain the human response (shivering) to a decrease in body temperature?

Answer 22

Rapid involuntary muscle contraction generates heat.

Question 23

Explain the human response (vasoconstriction) to a decrease in body temperature?

Answer 23

Decreased blood flow to the skin decreases heat loss by radiation.

Question 24

Explain the human response (contraction of hair erector muscles) to a decrease in body temperature?

Answer 24

Traps a layer of insulating air.

Question 25

What does an increase in metabolic rate also increase?

Answer 25

Increases heat production

Question 26

What is the maintenance of body temperature required for?

Answer 26

Its required for optimal enzyme activity

Question 27

What does the maintenance of body temperature ensure?

Answer 27

Ensures high diffusion rates required to maintain metabolism