1 markA cell membrane has a thickness of 10 nm.
What will happen to the rate of diffusion if the cell membrane thickness changed to 5 nm?
The rate of diffusion halves
There is no change in the rate of diffusion
The rate of diffusion is 5 times greater
The rate of diffusion doubles
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1 markWhich of the following correctly explains why mammals have a double circulatory system?
To reduce pressure of blood returning from the lungs to supply cells of the body most efficiently with the reactants for respiration
To increase the pressure of blood sent to the lungs to supply cells of the body most efficiently with the reactants for respiration
To increase the pressure of blood returning from the lungs to supply cells of the body most efficiently with the reactants for respiration
To reduce pressure of blood sent to the lungs to supply the cells most efficiently with the products for respiration
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1 markWhich of the following gives the correct location of the valves?
Arteries
Capillaries
Veins
Arteries and veins
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1 markWhich of the following statements correctly explains the effect of root hairs on absorption?
Provide a large surface area, maximising the rate of absorption of water and ions by osmosis
Provide a large surface area, maximising the rate of absorption of water by osmosis and ions by active transport
Increase the surface area, maximising the uptake of water by osmosis and ions by diffusion
Provide a large surface area, increasing the rate of absorption of water and ions by active transport
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1 markWhich one of the following graphs most closely represents the relationship between atmospheric humidity and the rate of transpiration from a leaf?
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1 markA student uses a simple potometer to study the effect of different temperatures on the cut shoot of a plant.
What does the potometer actually measure?
Volume of water evaporating from the leaves of the shoot
Volume of water produced by respiration in the shoot
Volume of water taken up by the shoot
Volume of water used in photosynthesis in the shoot
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1 markThe surface area of a single red blood cell is 1.5 × 10-4mm2.
The volume is 1 × 10-7mm3.
What is the surface area to volume ratio of a red blood cell?
0.0015 : 1
0.7 : 1
1.5 : 1
1500 : 1
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1 markThe diagram shows a red blood cell.
| Distance oxygen travels to get to haemoglobin from blood plasma |
Surface area to volume ratio |
Nucleus present | |
| A | Large | Small | Yes |
| B | Short | Large | Yes |
| C | Short | Large | No |
| D | Large | Large | No |
Which row in the table shows how red blood cells are adapted for transport of oxygen?
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1 markSieve plates are structures found in plants.
What is their location and function?
Found in phloem and allow movement of sucrose
Found in phloem and allow movement of water
Found in xylem and allow movement of sucrose
Found in xylem and allow movement of water
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1 markWhich type of plant cell takes in water?
Guard cell
Phloem cell
Root hair cell
Xylem cell
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1 markWhich type of human cell is shown in this diagram?
Egg cells
Red blood cells
Sperm cells
White blood cells
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1 markTranspiration has a cooling effect on the leaves of plants.
Which statement best describes how this happens?
Evaporation of water from the leaf removes heat energy.
Water entering the stomata takes heat energy from the leaf surface.
Water dripping off the leaf causes heat energy to be lost.
Water falling on the leaf removes heat energy.
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1 markWhich process takes water out of plant leaves into the air?
Osmosis
Photosynthesis
Translocation
Transpiration
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1 markWhich row shows the correct direction of blood flow through a double circulatory system?
| left side of heart | ⟶ | body organs | ⟶ | right side of heart | ⟶ | lungs |
| left side of heart | ⟶ | lungs | ⟶ | right side of heart | ⟶ | body organs |
| right side of heart | ⟶ | body organs | ⟶ | lungs | ⟶ | left side of heart |
| right side of heart | ⟶ | lungs | ⟶ | body | ⟶ | left side of heart |
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1 markHow is sugar transported around a plant?
Upwards in phloem
Upwards in xylem
Upwards and downwards in phloem
Upwards and downwards in xylem
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1 markWhich diagram shows cells that swell, creating an opening during daylight conditions?
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1 markWhich substances are absorbed from the soil by the root hair cell?
Carbohydrates and proteins
Carbon dioxide and nitrogen
Proteins and vitamins
Water and mineral ions
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1 markWhich process moves food around in plants?
Osmosis
Respiration
Translocation
Transpiration
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1 markSome plants can wilt if they lose more water than they take up.
Which conditions make a plant most likely to wilt?
Higher wind speed and lower temperature
Lower wind speed and lower temperature
Lower wind speed and higher temperature
Higher wind speed and higher temperature
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1 markThe graph shows total water loss from a plant.
Calculate the water lost between 5 and 15 minutes using the line of best fit.
2.2ml per 100g
2.4ml per 100g
2.6ml per 100g
2.8ml per 100g
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1 markMarram grass grows on sand dunes with very little water available. It has a leaf that is curled in on itself so that the stomata are hidden on the inside, as shown in the diagram.
Why does this adaptation help the plant to survive on sand dunes?
Increases gas exchange from the stomata.
Reduces air movement around the stomata.
Increases photosynthesis by the leaf.
Increases water uptake by the leaf.
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1 markA cube of potato is used to investigate the effect of surface area on osmosis.
The cube is 3 × 3 × 3cm.
What is the surface area to volume ratio of the cube?
1:2
2:1
6:1
1:6
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