Thermoregulation

Question 1

What happens when molecules get hotter

Answer 1

They move around faster. so chemical reactions speed up

Question 2

What happens if temperature becomes too high

Answer 2

Temperature can cause enzymes to denature

Question 3

What are the 2 ways animals regulate their body temp

Answer 3

Ectothermy and endothermy

Question 4

What are ectotherms

Answer 4

Animals that rely on external sources of heat to regulate their body temperature (cold blooded)

Question 5

What are endotherms

Answer 5

Animals that use heat from metabolic reactions to maintain their body temperature

Question 6

What are changes in temperature detected by

Answer 6

Temperature receptors in the thermoregulatory centre of the hypothalamus

Question 7

What occurs if the temperature receptors detect a change

Answer 7

Causes nervous and hormonal systems to send signals to effectors

Question 8

Where else are temperature receptors found

Answer 8

In the skin which also contact hypothalamus

Question 9

What is the purpose of temperature receptors in the skin

Answer 9

They warn the hypothalamus of oncoming changes to temperature before the blood temperature has changed

Question 10

How do ectotherms regulate their temperature

Answer 10

By using their behaviour

Question 11

What does an ectotherm do if it is too cold

Answer 11

• Move into the sun
• Expose more surface area to the sun
• Move towards warm surfaces

Question 12

What does an ectotherm do if it is too warm

Answer 12

• Move into the shade
• Expose less surface area to the sun
• Move underground

Question 13

What do endotherms have that ectotherms do not

Answer 13

An internal source of heat due to metabolic reactions releasing heat

Question 14

How do endotherms stay warm

Answer 14

• Insulate the internal sources of heat

Question 15

How do hair and feathers provide insulation

Answer 15

In cold hair and feathers stand on end, creating an insulating layer of air

Question 16

How can capillaries lower heat loss

Answer 16

Capillaries constrict so less blood flow is at skins surface so less heat is lost by radiation

Question 17

How can respiration effect temperature

Answer 17

Respiration can be increased by the liver releasing more energy stores for conversion into heat

Question 18

How can muscle contractions effect temperature

Answer 18

Spontaneous muscle contractions (shivering) can be used to generate hear

Question 19

How can sweat cool body down

Answer 19

Heat is removed from the body when the water in the sweat is evaporated. Water has high latent heat of evaporation, so sweat holds a lot of heat before it is removed in evaporation

Question 20

What do animals that cant sweat do

Answer 20

They pant which removes heat by evaporation of saliva

Question 21

How can capillaries increase heat loss

Answer 21

Capillaries close to the skin undergo vasodilation, so more blood will be at surface to give off heat radiation

Question 22

What is an advantage of being an endotherm

Answer 22

They can maintain their temperature despite changes in external temperatures. So they can be active in different temperatures in the day, so can inhabit colder parts of the earth

Question 23

What is a disadvantage of being an endotherm

Answer 23

They spend a lot of energy keeping warm, so they need to find a lot more food. Also much more likely to overheat