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.
Daisies in five quadrats: 4, 7, 0, 5, 9.
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]
3 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
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]
3 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
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]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
In a pond, frogs eat insects and herons eat frogs. A disease kills most of the frogs.
.1
Explain what is likely to happen to the number of insects in the pond.
[2 marks]
.2
Explain why the heron population may also decrease.
[2 marks]
.3
Give two resources that animals compete for.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
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.
051015202530510152025Cigarettes smoked per dayRisk compared with non-smokers1481522
.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.
