2.4 metabolism in conformers and regulators

Question 1

What do external factors affect?

Answer 1

the ability of an organism to maintain its metabolic rate

Question 2

give 3 examples of abiotic factors

Answer 2

• temperature
• salinity
• pH

Question 3

What is a conformer?

Answer 3

an organism who’s internal environment is directly dependant upon its external environment

Question 4

How do conformers maintain optimum metabolic rate?

Answer 4

behavioural responses

Question 5

Give one advantage and one disadvantage of being a conformer

Answer 5

advantage->low metabolic costs

disadvantage->narrow range of ecological niches

Question 6

What do behavioural responses allow conformers to do?

Answer 6

allow them to tolerate variation in their external environment to maintain optimum metabolic rate

Question 7

What is a regulator?

Answer 7

an organism which maintains their internal environment regardless of the external environment

Question 8

Give one advantage and one disadvantage to being a regulator

Answer 8

advantage -> larger range of possible ecological niches

disadvantage -> high metabolic costs

Question 9

What is the temperature monitoring centre of the mammalian brain?

Answer 9

hypothalamus

Question 10

What is the role of nerves?

Answer 10

information is communicated by electrical impulses through nerves to the effectors

Question 11

What is the role of effectors and what are they?

Answer 11

• parts of the body such as muscles or glands that respond to messages
• bring about corrective responses to return conditions to their optimum.

Question 12

What is the role of sweating in response to an increase in body temperature?

Answer 12

body heat is used to evaporate the water in the sweat, cooling the skin

Question 13

What is the role of vasodilation in response to an increase in body temperature?

Answer 13

skin arterioles become dilated (wider) allowing an increased volume of of blood to flow through the capillaries on the skin surface, increasing heat loss by evaporation

Question 14

What is the role of decreased metabolic rate in response to an increase in body temperature?

Answer 14

less heat produced

Question 15

What is the role of shivering in response to a decrease in body temperature?

Answer 15

muscle contraction generates heat

(no other card) sweat glands reduce sweat production

Question 16

What is the role of vasoconstriction in response to a decrease in body temperature?

Answer 16

skin arterioles become constricted (narrower) reducing the volume of blood that flows through the capillaries on the skin surface, so less heat is lost by radiation

Question 17

What is the role of the hair erector muscles contracting in response to a decrease in body temperature?

Answer 17

trap air, providing insulation and reducing heat loss

Question 18

What is the role of increased metabolic rate in response to a decrease in body temperature?

Answer 18

more heat produced

Question 19

What is the importance of thermoregulation?

Answer 19

-for optimal enzyme activity
-high diffusion rates
maintaining these contributes towards the ability to maintain high metabolic activity

Question 20

What is homeostasis?

Answer 20

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

Question 21

What is negative feedback?

Answer 21

the control mechanism by which homeostasis is achieved

Question 22

What are receptors?

Answer 22

special cells that constantly monitor the internal environment and detect changes

Question 23

What happens if a change from the optimum is detected?

Answer 23

a corrective mechanism is switched on and messages are sent to the effectors

Question 24

What are two ways that messages can travel in the body?

Answer 24

• nerve impulse

- hormones

Question 25

give a description of negative feedback control

Answer 25

• any change in a condition from the optimum is detected by receptors
• that switch on a corrective mechanism to restore the conditions to normal.
• The corrective mechanism is then switched off

Question 26

What is a thermoregulator?

Answer 26

mammals have a homeostatic mechanism to regulate their body temperature.

Question 27

What is the role of the hypothalamus?

Answer 27

• the temperature-monitoring centre
• It sends out electrical impulses through nerves to effectors, skin and body muscles which bring about corrective responses to return temperature to normal

Question 28

What happens if the body temperature increases above normal?

Answer 28

• thermoreceptors in the hypothalamus detect this increase
• send electrical impulses through nerves to effectors
• to bring around corrective responses

Question 29

What happens if the body temperature decreases below normal

Answer 29

the thermoreceptors in the hypothalamus detect this decrease and send electrical impulses through nerves to effectors to bring around corrective responses

Question 30

What are thermoreceptors?

Answer 30

heat-sensitive cells in the hypothalamus of mammals

Question 31

What do regulators use metabolism for?

Answer 31

to control their internal environment, increasing their range of possible ecological niches

Question 32

What is homeostasis?

Answer 32

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

Question 33

What is thermoregulation?

Answer 33

the maintenance of a constant internal temperature

Question 34

What does negative feedback use corrective responses for?

Answer 34

to reverse changes in internal temperature to return temperature to normal

Question 35

What happens to regulators when the external environment varies beyond tolerable limits for normal metabolic activity?

Answer 35

they are unable to maintain their internal environment