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Edexcel IGCSE Biology 2.93 The eye

Edexcel IGCSE Biology 2.93 The eye
Edexcel IGCSE Biology syllabusBiology 4BI1First assessment 2019

Practise applying skin thermoregulation to hot, cold and exercise contexts, including sweat-rate graphs and blood-vessel changes.

How this is tested

  • describe vasodilation or vasoconstriction using arterioles, capillaries and heat loss at the skin
  • explain sweating during exercise as evaporation that removes heat and helps maintain body temperature
  • calculate sweat volume from graph readings by converting a rate over a given time interval

Question 4

Question 4(a)

(a)

The diagram shows a section through the skin with some structures labelled.

Figure for Question 4(a) — Edexcel IGCSE Biology
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Question 4(a)(i)

(i)

Which structure is the sweat gland?

A

P

B

Q

C

S

D

T

[ 1 ]

Question 4(a)(ii)

(ii)

Which structure is a capillary?

A

Q

B

R

C

S

D

T

[ 1 ]

Question 4(a)(iii)

(iii)

Describe the changes that take place in the blood vessels in the skin if a person moves to a hot environment.

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