Ectotherms and Endotherms

Question 1

What is an ectotherm?

Answer 1

organism that relies on external sources of heat to regulate its body temp

Question 2

What are endotherms?

Answer 2

maintain their body temp within fairly strict limits, largely independent of external temperature

Question 3

What are the advantages to being an ectotherm?

Answer 3

use less of their food in respiration, need to find less food and can survive long periods without eating (snake several weeks), greater proportion of energy from food can be used for growth

Question 4

What are the disadvantages to being an ectotherm?

Answer 4

less active in cooler temps, may need to warm in morning before being active (lizards), great risk of predation, may not be capable of activity during winter as never warm enough so must have sufficient energy stores

Question 5

How does an ectotherm change to regulate its temperature?

Answer 5

change behaviour or physiology to increase or decrease heat loss

Question 6

What is the example of locusts being ectotherms?

Answer 6

orientate themselves to be side on to the sun when they need to warm up, too hot = move higher away from hot ground and face on to sun (less SA)

Question 7

What are 3 examples of animals that have physiological or anatomical adaptations to help exchange heat with their environment?

Answer 7

horned lizard, can alter SA by expanding/contracting rib cage, frilled lizard can use frill to help absorb heat, locusts increase abdominal breathing when hot (increase water evaporation and aid cooling)