thermoregulation

Question 1

endotherm hot

Answer 1

kangaroo panting: the saliva evaporates off the tongue cooling it down evaporation water - gas cooling licking wrists: as the saliva evaporates it cools the blood vessels underneath the wrists which is then circulated through the body and cools it evaporation water - gas cooling

Question 2

endotherm cold

Answer 2

polar bear hair under paws: low conduction allows them to stay warmer for longer hair: is clear and hollow trapping warm air and reduces convection allows them to stay warmer for longer

penguin:

• counter current heat exchange
• think skin on palms and feet
• insulating blubber
• feathers for insulation
• huddling
• lean back and balance on their heels

Question 3

ectotherm hot

Answer 3

marine iguana avoidance: burrows, shade, nocturnal

Question 4

ectotherm cold

Answer 4

turtle basking: lie exposed to the heat and sun radiation energy transferred through empty space

Question 5

kangaroo feedback loop

Answer 5

stimulus: rise in body temp receptor: thermoreceptors in skin and hypothalamus modulator: hypothalamus starts cooling method effector: glands in mouth, saliva glands, lungs response: panting feedback: lowers body temp

Question 6

endotherm

Answer 6

heats body temp from an internal heat production straight line on graph

• mammals and birds

Question 7

ectotherm

Answer 7

heats body temp from an external heat source fluctuates on graph

• reptiles, fish , amphibians

Question 8

dogs pant when they get hot

Answer 8

• to regulate body temp - evaporate water form the mouth - circulate cool air through the body

Question 9

you shiver on cold days

Answer 9

• brief contractions of muscles that produces heat

Question 10

goose bumps on a cold day

Answer 10

muscles contract causing the hairs to stand up and surrounding to protrude trying to warm up the body

Question 11

skin looks pink on hot days

Answer 11

when hot the blood vessels dilate becoming larger to attempt to cool the body filing with more blood

Question 12

cats look fatter on a cold day

Answer 12

they fluff their fur and store fat to keep them warm, decreasing convection

Question 13

people eat more during winter

Answer 13

cold weather causes metabolic activity to increase, people increase more to keep up with it in attempt to heat up their body

Question 14

small mammal lose more heat then large

Answer 14

small body has a larger surface area to volume ratio causing them to lose more body heat

Question 15

thermal window purpose

Answer 15

open during the day, close at night, reduces conduction

Question 16

adaptive value of tucking legs under their body at night

Answer 16

reducing surface area to keep warm and sheltering the thermal windows so they can retain heat, ambient temp is unable to transfer into the body

Question 17

explain how penguins reduce heat loss when standing on ice

Answer 17

• rock back onto heels - use a counter current exchange system
• warm artery moves from blood to feet
• cool vein moves from feet to heart
• heat is trasnfered from warm blood in the artery to cool blood in the vein
• blood is cooled by the time it reaches the feet reduing heat loss

Question 18

after the injection from penguins

Answer 18

temp of the foot increases while body temp decreases. the muscle relaxant causes vasodilation decreasing the ability of the counter current exchange therefore causing the feet to heat up therefore losing more heat via conduction decreasing the overall temp of the body

Question 19

rising the temp of the hypothalamus

Answer 19

made the animals think they were hot therefore causing them to try cool themselves down decreasing their body temp

Question 20

lowering the temp of the hypothalamus

Answer 20

made the animals think they were cold therefore causing them to try heat themselves up increasing their body temp

Question 21

negative feedback

Answer 21

when a response cancels or counteracts the original stimulus

Question 22

is an echidna ability to go into torpor in cold conditions adaptive

Answer 22

yes because it doesn’t have to use a lot of energy to survive, in cold conditions food is scarce by not regularly eating and by lowering metabolic rate they are able to survive for longer then if were awake

Question 23

how can an echidna generate body heat to wake up from torpor

Answer 23

generate body heat by having an increase in their metabolic rate as they wake up functions such as shivering allows muscles to conduct warmth throughout their body they can also fluff their fur to trap heat and keep warm

Question 24

what would you expect about its oxygen consumption if its generates its own heat

Answer 24

oxygen consumption increases as their metabolic rate increases, the heat beats faster and they breathe faster

Question 25

do platypus like cold or warm water

Answer 25

warm because it requires less energy to generate body heat

Question 26

can platypus regulate body temp in cold water

Answer 26

yes because they are an endotherm

Question 27

suggest how a platypus might produce heat to regulate its body temp

Answer 27

muscles activity, through activities such as swimming the muscles contract causing them to warm up

Question 28

suggest how a platypus might reduce heat loss to regulate body temp

Answer 28

burrows, reducing convection and conduction by burrowing in warm, humid spot out of water and wind

Question 29

radiation

Answer 29

energy transferred through empty space occurs wihtout direct contact

Question 30

conduction

Answer 30

occurs when the temp of the organism and the environemtn are different

• result of direct contact

Question 31

convection

Answer 31

• transmission of heat from a warmer region to a cooler region from the movement of liquid or gas
• air con

Question 32

evaporation

Answer 32

water - gas cooling

• occurs as energy is lost through a phase state change from water to water vapour
• occurs rapidly when the air is hot and dry

Question 33

endotherm and ectotherm

Answer 33

red is endotherm, les energy to stay warm when temp increases then uses energy to cool down

blue is ectotherm as rate increases when temp incresses as they need to cool the body down

Question 34

homeostasis

Answer 34

the maintanence of a constant internal environmental despite changes in the external environment

• maintains optimal conditions for enzyme activity and cell functions

Question 35

feedback loop functions of stages

Answer 35

1. stimulus : a change in the internal or external environemtn
2. receptor: sensory structure in the body which detects the stimulus and sends signal to modulator
3. modulator: centre in the brain which regulates the necessary action
4. effector: structure in the body that receives signals from the modulator and carries out the action needed eg muscle or gland
5. response : action carried out by the effector

Question 36

positive feedback

Answer 36

• response amplies the direction of the stimulus

Question 37

feedback loop for thermoregulation hot

Answer 37

1. increase in body temp above normal
2. increase detected by thermoreceptors in the skin and in the hypothalamus
3. hypothalamus sends signals via nerve and hormones to effectors
4. sweat glands, blood vessels in skin, body cells
5. increase in sweating, vasodilation of blood vessels in the skin, decrease metabolic rate, behavioural changes

Question 38

feedback loop for thermoregulation cold

Answer 38

1. decrease in body temp below normal
2. decrease detected by thermoreceptors in skin and hypothalamus
3. hypothalamus sends signals via nerve and hormones to effectors
4. blood vessels in skin, skeletal muscles, body cells
5. vascontriction of blood vessels in skin, shivering, increased metabolic rate, behavioural change

Question 39

endotherm vs ectotherm

Answer 39

ectotherm : metabolic rate increases with increase in temp

• can survive on less food
• low water requirment

endotherm: metabolic rate remains constant with increaseing temp

• needs high inputs of food to survive
• high water requirment