Grade 9 Biology diagnostic

16 questions on plant biology, cells & microscopy, human biology & physiology, genetics & inheritance, evolution & biodiversity, ecology & populations and measurement & evidence, plus 2 from Grade 8. Answer what you can, then check your answers to see which topics are secure and what to practise next.

16 questions7 topicsAbout 20 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, 89 of 196 seeds germinated under the stated test conditions. Find the sample germination percentage. Round to 3 decimal places if needed. Answer in %.

Your answer%

2Plant biologyWhere does much of the carbon in newly made plant sugar come from?

A. Only mineral particles from soil.B. Sunlight atoms.C. Carbon dioxide.

3Cells & microscopySupplied plant-tissue data show initial mass 7.3 g and final mass 7.2 g. Find signed percentage mass change. No experiment is required. Round to 3 decimal places if needed. Answer in %.

Your answer%

4Cells & microscopyWhich structure is found in plant cells but not in animal cells: the cell wall or the cell membrane?

A. the cell wallB. the cell membrane

5Human biology & physiologyA fictional circulation model has 96 beats/min and 44 mL/beat. Find its flow in mL/min. These are supplied model values, not diagnostic ranges. Round to 3 decimal places if needed. Answer in mL/min.

Your answermL/min

6Human biology & physiologyWhich is part of many chemical synapses?

A. Only sound waves in air.B. A released chemical messenger interacting with receptors.C. A new chromosome created at every message.

7Genetics & inheritanceIn pea plants, the allele for a tall stem (T) is dominant over the allele for a short stem (t). Two plants, tt × tt, are crossed. What percentage of the offspring are expected to have the genotype Tt?

Your answer%

8Genetics & inheritanceIn the simple Aa × Aa inheritance model with independent outcomes, the probability of aa is 1/4. Among 60 offspring, find the expected aa count, not a guaranteed outcome. Round to 3 decimal places if needed.

Your answer

9Evolution & biodiversityA trait occurs in 20 of 100 organisms, then 40 of 100 in a later sample. What is the increase in percentage points?

Your answer

10Evolution & biodiversityDuring the Industrial Revolution in England, soot darkened tree bark, and dark peppered moths became more common. Why?

A. Dark moths were harder for birds to see on dark bark, so more of them survived to reproduce.B. Soot changed the genes of light moths into dark ones.C. Moths painted themselves with soot.D. Birds preferred to eat dark moths.

11Ecology & populationsA supplied food-web model transfers 8% of 736 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.

Your answerkJ

12Ecology & populationsA supplied survey counts 39 plants in 3 non-overlapping quadrats, each 1 m². Find the mean density in the sampled area. Round to 3 decimal places if needed. Answer in plants/m².

Your answerplants/m²

13Measurement & evidenceInvestigation: Pots of the same kind of plant receive 0, 5, 10 or 15 g of fertilizer in the same type of soil, and the number of leaves is counted after a month. In this investigation, which is the independent variable?

A. the number of leavesB. the type of soilC. the mass of fertilizer

14Measurement & evidenceIndependent measured heights are 8, 10 and 12 cm. Find the mean.

Your answercm

From Grade 8

These questions check skills from the grade below, so gaps can be spotted early.

15Cells & microscopy (Grade 8)Which organelle is a site of photosynthesis in many plant cells?

A. Chloroplast.B. Animal lysosome.C. Ribosome.

16Ecology & populations (Grade 8)Which is a primary producer in this simple land food chain?

A. Grass.B. Rabbit.C. Fox.