B3 questions

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  • Created by: _Holly
  • Created on: 11-05-13 14:47
Name the main substances that diffuse out of leaves
Water and oxygen
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A solution of pure water is separated from a concentrated sugar solution by a partially permeable membrane. In which direction will molecules flow, and what substance will these molecules be?
Water molecules will flow towards the concentrated sugar solution because there are less water molecules there
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How are leaves adapted to maximise the amount of CO2 that gets to their cells?
CO2 diffuses through the stomata on the underside of the leaf. Oxygen and water vapour diffuse out of the stomata so there is more space for the CO2
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What conditions does evaporation of water from leaves happen most quickly in
Hot weather, dry weather and windy weather. All three mean even more water is lost.
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What happens during ventilation?
The intercostal muscles and diaphragm contract and so the thorax volume increases. This decreases the pressure, drawing air into the lungs. To breath out, the opposite happens and the pressure increases, forcing air out
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How do modern artificial ventilators work?
They pump air into the lungs which expands the ribcage. When they stop pumping, the ribcage relaxes and pushes air back out of the lungs (used for people with lung injury/disease or under general anaesthetic
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Give 4 ways that the alveoli's structure is ideal for gas exchange
Large surface area, good blood supply, short diffusion distance (to capillaries), moist lining for dissolving gases
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How does the structure of the villus make it good at its job?
They cover the small intestine so provide a big surface area, this means that digested food is absorbed much quicker into the blood. They have a single layer of surface cells and a very good blood supply to assist quick absorbtion
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Why is a root hair cell in the shape that it is?
They have a long 'hair' which sticks out into the soil to provide a big surface area for absorbing water and mineral ions from the soil
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Give the two main differences between active transport and diffusion
Diffusion is where particles move from a high to low concentration and active transport is where particles move from an area of high to low concentration. Diffusion doesn't require energy but active transport does
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Describe the role of the phloem
Phloem tubes transport food substances made in the leaves to growing regions and storage organs in the plant. Made of columns of living cells with small holes in the ends to allow stuff to flow through
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Describe the role of the xylem
Xylem tubes take water and minerals up from the roots to the stem and leaves in the transpiration stream. Made of dead cells joined end to end with no end walls between them and a hole down the middle
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What is the transpiration stream?
The constant pathway of water up the plant. Usually goes soil, roots and root hair, xylem, leaves, air
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Why is our circulation system a double circulation system?
We have two circuits joined together, the first pumps deoxygenated blood to the lungs to take in oxygen and the blood returns to the heart. The second pumps oxygenated blood around the body and returns to the heart deoxygenated
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Other cards in this set

Card 2

Front

A solution of pure water is separated from a concentrated sugar solution by a partially permeable membrane. In which direction will molecules flow, and what substance will these molecules be?

Back

Water molecules will flow towards the concentrated sugar solution because there are less water molecules there

Card 3

Front

How are leaves adapted to maximise the amount of CO2 that gets to their cells?

Back

Preview of the front of card 3

Card 4

Front

What conditions does evaporation of water from leaves happen most quickly in

Back

Preview of the front of card 4

Card 5

Front

What happens during ventilation?

Back

Preview of the front of card 5
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Comments

_Holly

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These are not finished questions, only about half of biology b3a, i will post the rest soon.

H@S@N

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This was useful and gave a variety of different topic questions 5 Stars

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