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4 marksIrritability and Response

CSEC Biology · May/June 2017 · Paper 2 · Question 4(a)(i)

Explain how structures in the human eye control the amount of light that enters the eye.

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Other parts of this question

  1. 4(a)(ii)Jenny enters a dimly lit room and cannot see the colours of the furniture until the lights are switched on. Explain how Jenny is able to discern objects in the…[5 marks]
  2. 4(b)A certain form of colour-blindness is inherited as a recessive allele carried on the X chromosome. It is thus said to be 'X-linked' or 'sex-linked'. A woman…[6 marks]

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