After a meal containing carbohydrates, the concentration of glucose in the blood rises.
.1
Explain how the body returns the blood glucose concentration to normal after the meal.
[3 marks].2
What is the cause of type 1 diabetes?
[1 mark]AQA GCSE Combined Science November 2020 Biology Paper 2F
5 questions on this paper's topics
25:001 of 5
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.
| 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]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 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]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]