Biology 1

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  • Created by: kelz0209
  • Created on: 11-04-14 13:22
Describe what happens at day 1 in the menstrual cycle.
Day 1 is when the bleeding starts.
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What is phototropism?
The growth of a plant in response to light.
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Name the plant hormone that controls phototropism.
Auxin.
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list four things that need to be kept constant within the body.
Water/ions/temperature/blood sugar level.
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Why is it important that the human body temperature is kept at about 37 degrees celcius?
This is the optimum temperature for most enzymes in the body.
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The menstrual cycle is controlled by several different hormones. What effect does oestrogen have on the release of FSH?
It inhibits/slows it.
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Which hormone causes an egg to mature in an ovary?
FSH.
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On what day of the menstrual cycle is the egg released?
Day 14.
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Oral contraceptive pills used to contain large amounts oestrogen. Explain how oestrogen can prevent pregnancy.
Keeping oestrogen levels permanently inbits/slows production of FSH, so no eggs mature/so egg developement and production stop.
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Modern contraceptive pills contain a much lower dosage of oestrogen.1.Give one advantage of taking these pills instead of the old high-oestrogen pills.2.Name one other hormone that is often used in contraceptive pills.
1.Low oestrogen pills have fewer side effects. 2.Progesterone.
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On a hot summer day Katie is running in the park, while Colin is sitting still at home reading a book. Will Colin or Katie be losing more water through their skin? Give one reason for your answer.
Katie. She will lose more water through her skin than Colin because she will be sweating more.
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On a hot summer day Katie is running in the park, while Colin is sitting still at home reading a book. Will Colin or Katie have more concentrated urine? Give one reason for your answer.
Katie. She wil have more concentrated urine than Colin because she will be losing more water by sweating(and breathing).
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Control of the body's water content is part of homeostasis. Explain what is meant by homeostasis.
All the functions of your body which try to mantain a constant internal environment.
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In 1918, a Hungarian scientist called Arpad Paal did experiments to investigate how plants grow. The diagram below shows one experiment he did. When a stem grows to the left as shown above, which side is growing faster?
The right side.
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Explain what makes the stems at the final stage grow to the left.
Auxin is produced in the tips and moves backwards/down the stem, so there is more auxin on the right side. This makes the cells grow faster on the right side, so the stem grows to the left.
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The stems wer kept in the dark after the tips were replaced. Explain why.
Because the light would change the distribution of the auxin.
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Plant hormones have several commercial uses. Explain why plant growth hormones are used to make selective weedkillers.
Selective weedkillers are made of plant hormone which only affect broad-leaved plants. So they kill weeds, but not (cereal)crops.
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Name one other commercial use for plant growth hormones.
Rooting powder.
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To keep cells working properly, the ion content of the body and the body temperature must be kept constant. 1.Which organ is responsible for regulating the ion content of the blood? 2.Which organ is responsible for regulating body temperature?
1.Kidney 2.Brain.
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Other cards in this set

Card 2

Front

What is phototropism?

Back

The growth of a plant in response to light.

Card 3

Front

Name the plant hormone that controls phototropism.

Back

Preview of the front of card 3

Card 4

Front

list four things that need to be kept constant within the body.

Back

Preview of the front of card 4

Card 5

Front

Why is it important that the human body temperature is kept at about 37 degrees celcius?

Back

Preview of the front of card 5
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