3.2 Coordination & Control – the Endocrine System

A group of students want to set up an experiment to investigate plant growth.

They attached a plant pot to a clinostat and placed it in a dark room as shown in the image below:

Which of the following images would show the expected result of this experiment after two days?

The graph shows the fluctuations in four hormones involved in the menstrual cycle.

Which line represents the hormone responsible for ovulation?

The graph shows usage of different forms of contraception in four groups of 100 women.

Each group used a different form of contraception.

Which is the least effective method of contraception?

Which statement correctly describes the effect of adrenaline on the body?

Plant shoots grow towards sunlight.

Which term describes this behaviour?

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Which hormone is used to ripen fruit?

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Which hormone is used to increase metabolic rate?

The diagram shows apparatus used in experiments on tropisms.


When the apparatus rotates, the root grows horizontally.

Which tropism is not showing its usual effect on the root?

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The level of thyroxine in the body is controlled by negative feedback.

The diagram shows how this takes place.

Which numbers on the diagram represent the hormones TSH and thyroxine?

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Which hormone is important in the fruit ripening process in plants?

Which hormone is involved in controlling the menstrual cycle?

Seedlings were grown with a light-proof cap over the tip. The seedlings had light from one direction only.

Which diagram shows the correct growth of the seedling after two days in these conditions?

Plant roots respond to gravity by growing downwards.

What is this response called?

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A side effect of some antibiotics is to inhibit the release of thyroxine into the blood.

What will these antibiotics do to levels of TSH and TRH?

When a woman reaches the age of about 50, eggs are released less often from her ovaries.
To try and correct this, her body increases the production of one hormone.

Which hormone is this?

Plants growing in swamps have special roots that grow upwards through waterlogged soil to get oxygen from air.

What type of response do these roots show?

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Why are plant hormones used to cause parthenocarpic fruit development?

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Thyroxine is a hormone controlled by negative feedback.

There is an increase in the metabolic rate of the body until the cells of the body have the required amount of energy.

Once the cells of the body have the required amount of energy what will happen to the levels of the three hormones in the blood?