A2 Biology Unit 5 Definitions

Question 1

Endotherm

Answer 1

An organism that uses internal heat regulation and metabolic process responses to maintain core body temperature.

Question 2

Ectotherm

Answer 2

An organism that relies on environmental heat sources to maintain core body temperature.

Question 3

Three ways heat can be transferred in the natural environment

Answer 3

Conduction
Convection
Radiation

Question 4

Heat-gain centre

Answer 4

Activated in response to a decrease in blood temperature (controls the mechanism that increases body temperature).

Question 5

Heat-loss centre

Answer 5

Activated in response to a increase in blood temperature (controls the mechanism that decreases body temperature).

Question 6

Responses to an increased body temperature

Answer 6

Decreased metabolic rate
Sweating
Vaso-dilation
Pilo-erector muscles relax

Question 7

Responses to a decreased body temperature

Answer 7

Increased metabolic rate
Shivering
Vaso-constriction
Pilo-erector muscles contract, raising body hair (goosebumps)