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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 2 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, 39 of 50 seeds germinated under the stated test conditions. Find the sample germination percentage. Round to 3 decimal places if needed. Answer in %.
%
2Plant biologyA sample has 40 seeds and 30 germinate under the stated test conditions. Find the germination percentage.
%
3Plant biologyWhich is a suitable control in a comparison of air-movement effects?
4Cells & microscopySupplied plant-tissue data show initial mass 13.9 g and final mass 14.3 g. Find signed percentage mass change. No experiment is required. Round to 3 decimal places if needed. Answer in %.
%
5Cells & microscopyA cell is modeled as a cube of side 4 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
6Cells & microscopyA printed image is 54 mm long at 50× magnification. Find the actual length in micrometers. Round to 3 decimal places if needed. Answer in µm.
µm
7Human biology & physiologyWhat is a typical role of amylase?
8Human biology & physiologyWhat helps maintain a diffusion gradient at lungs?
9Human biology & physiologyIn a simplified equation, one glucose yields 6 CO₂. How many CO₂ molecules correspond to 3 glucose molecules?
10Ecology & populationsA supplied food-web model transfers 19% of 898 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
11Ecology & populationsA fictional population starts at 237. During one interval: 49 births, 36 arrivals, 38 deaths and 24 departures. Find the final count. Round to 3 decimal places if needed.
12Ecology & populationsA supplied survey counts 76 plants in 6 non-overlapping quadrats, each 0.25 m². Find the mean density in the sampled area. Round to 3 decimal places if needed. Answer in plants/m².
plants/m²