Temperature control in ecotherms

Question 1

What is an ecotherm

Answer 1

an organism that relies on external sources of heat to maintain heat

Question 2

What is an endotherm

Answer 2

an organism that uses heat from metabolic reactions to maintain body temperature.

Question 3

What happens when temperature rises

Answer 3

molecules have more kinetic energy, they move about more quickly and collide more frequently. chemical reactions occur quicker.

Question 4

When temperature drops

Answer 4

there is less kinetic energy meaning that chemical reactions occur slowly.

Question 5

What is the effect of increasing temperature on proteins

Answer 5

many proteins have metabolic functions such as enzymes that increase the rate of biological reaction.
So increasing temp up to a certain point would increase the rate of reaction

Question 6

If temperature increases too much it can affect enzymes because

Answer 6

enzymes are globular proteins so have a specific tertiary structure, so shape of active site is complementary to substrate. So increase temp to much denatures ( change the shape) of the enzyme. So function is then lost.

Question 7

How do Endotherms control their body temperature?

Answer 7

with very strict limits. uses a variety of mechanisms to control body temperature and independent of external temperatures.

Question 8

How do Ecotherms control their body temperature?

Answer 8

not able to control their body temperature as effectively as endotherms. They rely on external sources of heat and their body temperature fluctuates with external temperatures. Using various behavioural mechanisms some ecotherms are able to control their body temperature.

Question 9

If ecotherms are not warm warm enough they try to absorb heat from environment by:

Answer 9

• moving to a sunny area
• lying on a warm surface
• exposing a large surface area to the sun

Question 10

If ecotherms are too hot they try increasing heat loss by:

Answer 10

• moving out of the sun
• moving underground
• reducing the body surface exposed to the sun.

Question 11

Example of ectotherm: Snake

Answer 11

Basks in the sun- absorbs heat directly from the sun.

Question 12

Example of ectotherm: Lizard

Answer 12

Many lizards use burrows or crevices between rocks. They hide during the hottest part of the day and coolest part of the night. - a burrow tends to have a more stable temperature than air.

Question 13

Advantage of ectothermy

Answer 13

They do not use up energy to keep warm as use external sources therefore;
- less of food is used in respiration
- more of energy and nutrients gained from food can be converted to growth
- they need to find less food.
- they can survive for long periods without food.

Question 14

Disadvantages of ectothermy

Answer 14

• less active in cooler temperatures
  so at risk from predators while they are cold and unable to escape.
  Cannot take advantage of food that is available while they are cold.