5090_w19_qp_12
A paper of Biology, 5090
Questions:
40
Year:
2019
Paper:
1
Variant:
2
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3
Discs of raw potato tissue are weighed (initial mass). They are then placed in sucrose solutions of different concentrations. After one hour their masses are measured again (final mass). The graph shows how the ratio of initial mass : final mass changes with concentration of sucrose solution. 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.1 0.2 0.3 0.4 0.5 initial mass final mass concentration of sucrose solution / mol per dm3 Which concentration of sucrose solution has the same water potential as that of the cells in the potato discs?
3. Movement into and out of cells  →  3.1. Diffusion and osmosis
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29
A square metre of grassland receives 1 004 000 kJ of sunlight energy per year. The table shows what happens to this energy. process energy / kJ evaporation of water from the ground 500 000 absorption by the ground 330 000 reflection from leaf surfaces 150 000 formation of new grass leaves 22 000 metabolism of grass plants (other than growth or respiration) 1 500 heat loss via grass plant respiration How much of the 1 004 000 kJ of sunlight energy was used by the grass plants?
19. Relationships of organisms with one another and with the environment  →  19.1. Energy flow
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37
A student wrote some statements about chromosomes, but made a number of mistakes. There are 46 pairs of chromosomes in a human body cell. In gametes, chromosomes are found in pairs. Males have one X and one Y chromosome in each body cell. Chromosomes contain a long DNA molecule divided into sections called genes. Chromosomes include genes which are divided into sections called DNA molecules. Which two statements are correct?
16. Development of organisms and continuity of life  →  16.1. Nuclear division
17. Inheritance  →  17.3. Inheritance
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