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Grade 8 · Biology

Grade 8 Biology diagnostic

12 questions on plant biology, cells & microscopy, human biology & physiology and ecology & populations. Answer what you can, then check your answers to see which topics are secure and what to practise next.

12 questions4 topicsAbout 15 minutesSet 1 of 5

Skip a question if you do not know the answer. It is better than guessing, because it shows what to practise.

1Plant biologyIn supplied data, 42 of 124 seeds germinated under the stated test conditions. Find the sample germination percentage. Round to 3 decimal places if needed. Answer in %.
%
2Plant biologyWhich tissue is associated with water and mineral transport?
3Plant biologyWhich event is fertilization?
4Cells & microscopySupplied plant-tissue data show initial mass 14.3 g and final mass 17.3 g. Find signed percentage mass change. No experiment is required. Round to 3 decimal places if needed. Answer in %.
%
5Cells & microscopyA printed image is 19 mm long at 200× magnification. Find the actual length in micrometers. Round to 3 decimal places if needed. Answer in µm.
µm
6Cells & microscopyA cell is modeled as a cube of side 19 µm. Find surface area divided by volume. This geometry is a simplified model. Round to 3 decimal places if needed. Answer in µm⁻¹.
µm⁻¹
7Human biology & physiologyWhy does a large exchange surface help gas transfer?
8Human biology & physiologyIs breathing identical to cellular respiration?
9Human biology & physiologyWhat defines a vein?
10Ecology & populationsA supplied survey counts 32 plants in 7 non-overlapping quadrats, each 0.5 m². Find the mean density in the sampled area. Round to 3 decimal places if needed. Answer in plants/m².
plants/m²
11Ecology & populationsA fictional population starts at 548. During one interval: 13 births, 38 arrivals, 51 deaths and 11 departures. Find the final count. Round to 3 decimal places if needed.
12Ecology & populationsA supplied food-web model transfers 14% of 822 kJ to the next level. Find transferred energy. The stated efficiency is not a universal ecological constant. Round to 3 decimal places if needed. Answer in kJ.
kJ