M5 C15: homeostasis

Question 1

what is homeostasis?

Answer 1

maintaining a dynamic equilibrium with fluctuations over a narrow range

Question 2

why does homeostasis include fluctuations over a narrow range?

Answer 2

impossible to be completely stable within the body

Question 3

what are some factors controlled by homeostasis?

Answer 3

temperature
urea concentration
blood glucose conc
blood ph

Question 4

what is negative feedback?

Answer 4

when a increase or decrease in conditions is detected the body will either have a response so the body goes back to ideal conditions

Question 5

what are some examples of negative feedback?

Answer 5

insulin- lowers blood glucose conc by converting glucose to glycogen
glucagon- increases blood glucose conc by converting glycogen to glucose

Question 6

what is positive feedback?

Answer 6

when a change is detected in conditions, a response reinforces the change.

Question 7

what are some example of positive feedback?

Answer 7

blood clotting
depolarisation
contractions

Question 8

thermoregulation

Answer 8

maintenance of a relatively constant core body temp

Question 9

why is maintaining a constant core body temp good?

Answer 9

maintains optimum enzyme activity

Question 10

what is an ectotherm?

Answer 10

animals that use their surroundings to warm their bodies

Question 11

what is an endotherm?

Answer 11

animals that rely on metabolic processes to warm up and maintain a stable temp

Question 12

what are behavioral responses?

Answer 12

change in how organisms behaves to different stimuli

Question 13

what are physiological responses?

Answer 13

automatic responses to stimulus due to physiological features of an organism

Question 14

what is conduction?

Answer 14

heating due to collision of particles/molecules

Question 15

are gases, solids or liquids good conductors?

Answer 15

gases- poor due to low freq of collisions
liquids + solids - good due to particles being close together

Question 16

what is convection?

Answer 16

heating and cooling due to currents of air.
e.g. warm air rises, but cools down the higher it is. this then sinks and warms up again as it is closer to the ground.

Question 17

what is radiation?

Answer 17

heating and cooling by transmission of electromagnetic waves to and from a source

Question 18

what type of organisms are ectotherms?

Answer 18

fish
amphibians
reptiles
invertebrate animals

Question 19

why are most aquatic animals ectotherms?

Answer 19

they live in water, which has a high heat capacity. this means it doesn’t change temperature easily so they don’t need to thermoregulate themselves

Question 20

what are some behavioural responses a ectotherm could do to warm up?

Answer 20

increasing SA towards sun
vibrating
pressing body against warm ground
bating in sun

Question 21

what are some physiological responses a ectotherm could do to warm up?

Answer 21

increase heart rate
darker colour

Question 22

what are some behavioural responses a ectotherm could do to cool down?

Answer 22

hide in cracks
reduce movements
face body away from sun

Question 23

what are some physiological responses a ectotherm could do to cool down?

Answer 23

decrease metabolic rate

Question 24

why can ectotherms live in environments with limited food?

Answer 24

because they need less energy to maintain a constant core body temp to regulate temp

Question 25

what is a disadvantage of ectotherms?

Answer 25

affected by fluctuations in the environment