Question 1
4 marksA sheep farmer wants his flock to produce more wool. He uses selective breeding.
(a)
What is meant by selective breeding?
(b)
Describe how the farmer could use selective breeding to produce sheep that give more wool.
Genetic Modification Practice Questions
Question 2
4 marksBacteria can be genetically engineered to make human proteins such as insulin.
(a)
What is meant by genetic engineering?
(b)
Complete the table by naming the enzyme or structure described.
| Description | Name |
|---|---|
| An enzyme that cuts DNA at a specific base sequence | |
| An enzyme that joins the gene into the cut plasmid | |
| A structure, such as a plasmid, used to carry a gene into a host cell |
Question 0
6 marksA plant nursery has one orchid plant that produces unusually large flowers. The nursery uses tissue culture to produce many more plants like it.
(a)
Describe the process of tissue culture.
(b)
Explain why all the orchid plants produced by tissue culture have large flowers.
(c)
Give one advantage of tissue culture in plant breeding programmes and one advantage of tissue culture in medical research.
Question 0
5 marksHuman growth hormone can be made by genetically engineered bacteria. The diagram shows a plasmid that has been cut open and a piece of human DNA containing the gene for growth hormone.
(a)
The same restriction enzyme is used to cut the human DNA and the plasmid. Explain why.
(b)
State the role of the enzyme ligase in this process.
(c)
After the plasmid has been taken up by a bacterium, explain how large amounts of human growth hormone are produced.
Question 0
6 marksBt maize is a genetically modified crop. It contains a gene from the bacterium Bacillus thuringiensis.
A farmer grew Bt maize and non-GM maize in neighbouring fields for one season. The results are shown in the table.
| Type of maize | Mean yield in tonnes per hectare | Number of insecticide sprays used |
|---|---|---|
| non-GM maize | 8.4 | 5 |
| Bt maize | 10.5 | 1 |
(a)
Calculate the percentage increase in mean yield of the Bt maize compared with the non-GM maize.
(b)
Explain how the gene from Bacillus thuringiensis increases the yield of the maize.
(c)
Give two disadvantages of growing Bt maize.
Question 0
5 marksA grower produces tomatoes in a large greenhouse. The plants are attacked by whitefly, an insect pest.
The grower treated one greenhouse with a chemical pesticide and another greenhouse with a parasitic wasp that lays its eggs in whitefly larvae (biological control). The mean number of whitefly per plant is shown in the table.
| Weeks after treatment | Mean number of whitefly per plant (pesticide) | Mean number of whitefly per plant (parasitic wasp) |
|---|---|---|
| 0 | 40 | 40 |
| 2 | 4 | 28 |
| 4 | 6 | 12 |
| 6 | 22 | 5 |
| 8 | 35 | 4 |
(a)
The grower also adds fertiliser to the soil. Explain how using fertiliser increases the yield of tomatoes.
(b)
Use the data in the table to compare the effect of the pesticide with the effect of the biological control.
(c)
Give one disadvantage of using biological control instead of a pesticide.
Question 0
6 marksPedigree dogs are produced by selective breeding. The table shows the percentage of dogs affected by an inherited hip disorder in two groups of dogs.
| Group of dogs | Percentage of dogs affected by the hip disorder |
|---|---|
| one pedigree breed | 24 |
| mixed-breed dogs | 6 |
(a)
Explain why selective breeding reduces genetic variation in a breed of dog.
(b)
Using the data in the table, explain why selective breeding can be harmful to a breed of dog.
(c)
Describe two ways that a breeding programme could maintain genetic variation in a breed of dog.
Question 0
6 marksIn some parts of the world the soil is becoming too salty for wheat to grow well. A plant scientist wants to develop a variety of wheat that can grow in salty soil. Two methods are possible:
- selective breeding from existing wheat plants that survive best in salty soil
- genetic engineering, transferring a salt-tolerance gene from a wild grass into wheat.
Evaluate the use of genetic engineering compared with selective breeding to produce the new variety of wheat.