StudyBrixFree worksheets, study guides and courses

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 3 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, 29 of 181 seeds germinated under the stated test conditions. Find the sample germination percentage. Round to 3 decimal places if needed. Answer in %.
%
2Plant biologyWhich is a suitable control in a comparison of air-movement effects?
3Plant biologyWhat does dispersal describe?
4Cells & microscopyA printed image is 3 mm long at 400× magnification. Find the actual length in micrometers. Round to 3 decimal places if needed. Answer in µm.
µm
5Cells & microscopyA cell is modeled as a cube of side 28 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 & microscopySupplied plant-tissue data show initial mass 11.8 g and final mass 12.6 g. Find signed percentage mass change. No experiment is required. Round to 3 decimal places if needed. Answer in %.
%
7Human biology & physiologyWhy are thin exchange barriers useful?
8Human biology & physiologyWhat is a typical role of amylase?
9Human biology & physiologyWhat does aerobic refer to in the standard respiration model?
10Ecology & populationsA supplied survey counts 37 plants in 4 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
11Ecology & populationsA supplied food-web model transfers 22% of 1310 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
12Ecology & populationsA fictional population starts at 438. During one interval: 42 births, 7 arrivals, 30 deaths and 27 departures. Find the final count. Round to 3 decimal places if needed.