Grade 12 Biology diagnostic

15 questions on cells & microscopy, human biology & physiology, genetics & inheritance, ecology & populations and measurement & evidence, plus 3 from Grade 11. Answer what you can, then check your answers to see which topics are secure and what to practise next.

15 questions5 topicsAbout 15 minutesSet 4 of 5

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

1Cells & microscopyWhich structure does a typical bacterial cell have: the mitochondrion or the cell membrane?

A. the mitochondrionB. the cell membrane

2Cells & microscopyWhat separates during mitotic anaphase?

A. Entire species.B. Sister chromatids.C. Only all cell membranes.

3Human biology & physiologyA fictional circulation model has 68 beats/min and 41 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

4Human biology & physiologyDoes homeostasis mean every internal value is exactly constant?

A. Yes, with no fluctuations.B. No; regulation operates within ranges.C. Only because cells stop working.

5Genetics & inheritanceIn a canonical double-stranded DNA sample, adenine is 28% of all bases. Find the guanine percentage, assuming A = T and C = G. Round to 3 decimal places if needed. Answer in %.

Your answer%

6Genetics & inheritanceUsing base-pairing rules, which sequence pairs with the DNA strand TGAATGT, read base by base in the same order?

A. ACTTACAB. ACTTGCAC. ACUUACAD. TGAATGT

7Genetics & inheritanceA fictional diploid organism has 62 chromosomes in a normal somatic nucleus. In the standard meiosis model, how many chromosomes are in a haploid gamete? Round to 3 decimal places if needed.

Your answer

8Ecology & populationsA fictional population starts at 291. During one interval: 18 births, 2 arrivals, 32 deaths and 35 departures. Find the final count. Round to 3 decimal places if needed.

Your answer

9Ecology & populationsIn this simplified food chain: grass → rabbit → fox. If the population of “fox” suddenly drops, what is the most likely short-term effect on the population of “rabbit”?

A. It will most likely increase.B. It will not be affected at all.C. It will most likely decrease.

10Ecology & populationsSupplied fictional records give M = 71 initially marked, C = 64 in a later sample, and R = 8 marked in that sample. Use N ≈ MC/R under the stated assumptions. No animals are to be handled. Round to 3 decimal places if needed.

Your answer

11Measurement & evidenceInvestigation: Yeast is mixed with sugar water at 20 °C, 30 °C and 40 °C, using the same mass of sugar each time, and the gas bubbles released per minute are counted. In this investigation, which is a controlled variable?

A. the mass of sugarB. the number of gas bubbles per minuteC. the temperature

12Measurement & evidenceDo ten readings of one plant equal ten independently grown plants?

A. Yes, always.B. Only if recorded in different pens.C. No.

From Grade 11

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

13Human biology & physiology (Grade 11)What defines a vein?

A. It carries blood toward the heart.B. It always contains no oxygen.C. It transports only air.

14Evolution & biodiversity (Grade 11)Which data can contribute to classification?

A. Only market price.B. Molecular sequences and anatomical traits.C. Only a favorite common name.

15Ecology & populations (Grade 11)A supplied food-web model transfers 15% of 608 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