Explain why a decrease in the number of rabbits could affect the population of foxes and grass.
23 marks
A student placed 10 quadrats of 1 m² randomly in a field of area 1200 m² and counted 48 daisies in total. Estimate the number of daisies in the field.
34 marks
Describe the processes that cycle carbon between the atmosphere and living things.
43 marks
Explain the terms gene, allele and genotype.
54 marks
Explain how natural selection could lead to the evolution of camouflaged moths.
63 marks
Explain why the three-domain system replaced the five-kingdom system.
74 marks
Describe how measles and HIV are spread and how the spread can be reduced.
86 marks
Explain how a vaccine protects a person against a disease.
94 marks
Describe the stages in developing a new drug.
104 marks
Explain how smoking increases the risk of cardiovascular disease and lung cancer.
114 marks
Describe the process of selective breeding of cattle for high milk yield.
126 marks
Explain how human activities reduce biodiversity and describe ways to protect it.
134 marks
Describe four factors that threaten food security.
144 marks
Describe how abiotic and biotic factors can affect a community, giving two examples of each.
153 marks
A student placed 20 quadrats of 1 m² randomly in a field of area 5000 m² and counted 37 daisies in total. Estimate the number of daisies in the field.
161 mark
Which term describes having two identical alleles for a gene?
Finished?
Answer every question to finish (16 left), or finish when the time’s up.
Score 0 / 60 · 0 of 16 marked
This paper is written by Plasmo in the style of the OCR GCSE Combined Science exam. It is not a past paper and is not produced or endorsed by the exam board.