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Photosynthesis

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Question 2

Red algae are photosynthetic organisms that are adapted to live in deep marine environments where only certain wavelengths of light can penetrate.

A researcher studied red algae under different light conditions and made the following observations:

  • Red algae appear red in colour under white light.
  • At low light intensities, the rate of oxygen production is low.
  • Above a certain light intensity, the rate of oxygen production remains constant even if the light intensity is increased further.

Which of the following statements correctly explains these observations?

A

The pigments in red algae absorb red light, and light intensity is a limiting factor for the rate of photosynthesis.

B

The pigments in red algae absorb blue-green light, and light intensity is a limiting factor for the rate of photosynthesis.

C

The pigments in red algae absorb red light, and light intensity is not a limiting factor for the rate of photosynthesis.

D

The pigments in red algae absorb blue-green light, and light intensity is not a limiting factor for the rate of photosynthesis.

Markscheme

Photosynthesis Questions

  1. A Level
  2. /Biology
  3. /Photosynthesis

16 exam-style questions on OCR A A Level Biology Photosynthesis. Each one has a worked solution and a mark scheme showing where the marks go.

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