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
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]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
Some strains of bacteria are resistant to antibiotics. MRSA is resistant to several antibiotics.
.1
Explain how a population of bacteria becomes resistant to an antibiotic.
[4 marks]
.2
Give two ways to reduce the rate at which antibiotic-resistant strains develop.
[2 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A student measured his reaction time. His partner held a ruler with the 0 cm mark level with the top of the student's thumb, then dropped it without warning. The student caught it as quickly as possible, and the partner read the distance fallen.
Conversion table from distance fallen to reaction time: 10 cm, 0.143 s; 11 cm, 0.150 s; 12 cm, 0.156 s; 13 cm, 0.163 s; 14 cm, 0.169 s; 15 cm, 0.175 s.
Distance fallen (cm)
10
11
12
13
14
15
Reaction time (s)
0.143
0.150
0.156
0.163
0.169
0.175
.1
In five trials the ruler fell 15 cm, 12 cm, 14 cm, 11 cm and 13 cm.
Calculate the mean distance.
[2 marks]
.2
Use the conversion table to give the student's mean reaction time.
[1 mark]
.3
Give two variables the student should control to make his results valid.
[2 marks]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
The body keeps its temperature close to 37 °C.
.1
Explain why it is important to keep body temperature close to 37 °C.
[2 marks]
.2
Which of these is an effector?
[1 mark]
.3
Name the coordination centre that receives information from temperature receptors.
