Original questions for every module, with worked explanations and feedback on written answers.
Section I style
Multiple choice, worked or timed
Section II style
Short answers on a stimulus
Written answers
Read against the mark points, with your next step
Try 4 questions
Question 1
Grain set in the three groups of wheat florets
Group
Treatment
Florets that set grain (of 50)
1
anthers removed, bagged, pollen of Q added
41
2
anthers removed, bagged, no pollen added
7
3
untreated
46
In a hypothetical trial, a plant breeder near Wagga Wagga crossed two wheat varieties. In group 1 she removed the anthers from 50 florets of variety P before they shed pollen, covered the florets with paper bags, and later dusted them with pollen from variety Q. Group 2 had the same treatment but was given no pollen. Group 3 was 50 untreated florets of variety P. Which conclusion about the method do the results support?
Question 2
Growth of five colonies on agar containing each antibiotic
Colony
Grows on ampicillin
Grows on tetracycline
1
no
no
2
yes
yes
3
yes
no
4
yes
yes
5
yes
no
A plasmid carries two resistance genes, one for ampicillin and one for tetracycline. A human gene is inserted into the middle of the tetracycline resistance gene, so that gene no longer works. After bacteria are mixed with the plasmids, five colonies are tested for growth on agar containing each antibiotic. Which colonies carry the recombinant plasmid with the human gene?
Question 3
New cases of malaria in two villages over one year
Village
Bed nets used
Population
New cases per 1000 people
Village A
Yes
2400
12
Village B
No
2100
48
A study in two similar villages in South East Asia recorded new cases of malaria over one year. By what percentage was the incidence lower in the village that used insecticide-treated bed nets?
Question 4
Sweat chloride results in one family (hypothetical data)
Family member
Has cystic fibrosis
Sweat chloride (mmol/L)
Mother
no
22
Father
no
25
Ava (daughter)
yes
98
Leo (son)
no
20
Cystic fibrosis is an autosomal recessive disease. In a hypothetical family, a sweat chloride test above 60 mmol/L indicates cystic fibrosis (see the table). Leo plans a family with a partner whose genetic test shows she is a carrier. What is the probability that their first child will have cystic fibrosis?