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Explain why glucose is needed for the contraction of skeletal muscle.

Skeletal muscle use glucose in glycolysis to generate ATP, the energy currency of the cell. ATP binds the myosin head in skeletal muscle to displace actin (a protein bound as part of the muscle contractio...

Answered by • Biology tutor

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Draw a diagram showing a normal iris and what happens to the iris when a light in shined into the human eye. (1 mark). What causes this to happen? (2 marks)

(Any diagram showing an iris that has constricted) 1 mark
In high light levels (1 mark) Accept reflex action due to increased photoreceptor action or words to that effect
circular muscles relax ...

Answered by James P. • Biology tutor

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How is blood glucose levels controlled by the body (homeostasis) ?

Controlling high blood glucoseBlood glucose levels are important to control because glucose is our key source of energy in respiration. When blood glucose levels are too high, this...

Answered by Nazeya B. • Biology tutor

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Using your knowledge of osmosis, describe what happens to a red blood cell when they are placed in a beaker of distilled water.

The distilled water is a hypotonic solution and so has a higher water potential than that of the red blood cell. Due to the difference in water potentials, water will move from the beaker into the red blo...

Answered by Karishma R. • Biology tutor

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Putting bee honey on a cut kills bacteria. Honey contains a high concentration of sugar. Use your knowledge of water potential to suggest how putting honey on a cut kills bacteria.

Sugar is a solute, so honey contains a high concentration of solutes. This increases the solute potential, and decreases the water potential of honey, which is therefore lower than the water potential in ...

Answered by Nighat K. • Biology tutor

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