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]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
White blood cells help to defend the body against pathogens.
.1
What are the molecules on the surface of a pathogen that white blood cells recognise as foreign?
[1 mark]
.2
Describe three ways white blood cells defend the body against pathogens.
[3 marks]
.3
A person has antibodies against the measles virus. These antibodies do not protect the person against the mumps virus.
Explain why.
[2 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
The body cells of a species of fish contain 30 chromosomes, in 15 pairs.
.1
Give the number of chromosomes in one of this fish's gametes.
[1 mark]
.2
Give the number of chromosomes in a fertilised egg cell of this fish.
[1 mark]
.3
Describe what happens to the chromosomes when a cell divides by meiosis to form gametes.
[3 marks]
7 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
New drugs are tested in clinical trials.
.1
Give three things that new drugs are tested for.
[3 marks]
.2
Some patients in the trial are given a placebo.
Explain why.
[2 marks]
.3
Describe what is meant by a double-blind trial.
[2 marks]
5 marksFoundation
Spec and skills
Original practice question
Answer and supported method checks
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.
