Evolution is a change in the inherited characteristics of a population over time through natural selection.
.1
Put the stages of natural selection in order, starting with the first.
[2 marks].2
Define the term species.
[1 mark]OCR Gateway GCSE Biology November 2021 Paper 2
5 questions on this paper's topics
21:001 of 5
A student estimated the number of daisies in a field 50 m long and 40 m wide. She placed a 0.25 m² quadrat at five random positions and counted the daisies in each.
| Quadrat | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| Number of daisies | 4 | 7 | 0 | 5 | 9 |
.1
Calculate the mean number of daisies per quadrat.
[2 marks].2
Estimate the number of daisies in the whole field.
[3 marks]Scientists studied the risk of lung cancer in adults who smoked different numbers of cigarettes each day. The graph shows how many times greater the risk was than for non-smokers.
.1
Describe the pattern shown in the graph.
[1 mark].2
Calculate how many times as great the risk is for a person smoking 20 cigarettes a day as for a person smoking 5 a day.
[1 mark].3
A correlation does not always mean that one factor causes another.
Explain what other evidence scientists needed before concluding that smoking causes lung cancer.
[2 marks]Peat bogs are areas of partly decayed plant material that has built up over thousands of years. Peat is dug up to make garden compost.
.1
Explain why destroying peat bogs increases the amount of carbon dioxide in the atmosphere.
[2 marks].2
Give one other reason why destroying peat bogs is harmful.
[1 mark]A couple already have three daughters. They are expecting a fourth child.
.1
Give the probability that the fourth child will be a boy.
[1 mark].2
Explain why the chance of any baby being a boy is 50%.
[2 marks]