9700_w21_qp_13
A paper of Biology, 9700
Questions:
40
Year:
2021
Paper:
1
Variant:
3
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15
The cells in the roots of beetroot plants contain a red pigment. When pieces of root tissue are soaked in cold water, some of the red pigment leaks out of the cells into the water. An experiment was carried out to investigate the effect of temperature on the loss of red pigment from the root cells. It was found that the higher the temperature of the water, the higher the rate of loss of red pigment from the root cells. Which statements could explain this trend?
4. Cell membranes and transport  →  4.2. Movement into and out of cells
13. Photosynthesis  →  13.2. Investigation of limiting factors
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17
A single-celled organism lives in freshwater. Water that enters the cytoplasm of the cell by osmosis is collected into a structure called the contractile vacuole. To remove the water the contractile vacuole fuses with the cell surface membrane. A student counted the number of times that the contractile vacuole filled and emptied when the cell was placed in solutions with different water potentials. The results are shown...
4. Cell membranes and transport  →  4.2. Movement into and out of cells
Open
26
In an investigation, a leafy shoot was attached to a potometer and exposed to a variety of conditions. The time taken for the meniscus to move 50 mm along the capillary tubing was recorded for each set of conditions. temperature / C humidity air movement time taken to move 50 mm / s dry not moving dry moving dry not moving humid not moving humid moving humid not moving Which row shows the slowest and fastest rates of water uptake for this investigation?
7. Transport in plants  →  7.2. Transport mechanisms
4. Cell membranes and transport  →  4.2. Movement into and out of cells
Open
28
The statements list some of the events in the cardiac cycle. They are not in the correct order. The impulse travels through Purkyne tissue. A wave of excitation sweeps across the atria. The atrioventricular node delays the impulse for a fraction of a second. The sinoatrial node contracts. The wave of excitation sweeps upwards from the base of the ventricles. The ventricles contract. The atria contract. Which statement describes the sixth of these events to occur in the cardiac cycle?
8. Transport in mammals  →  8.3. The heart
15. Control and coordination  →  15.1. Control and coordination in mammals
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