Genetic engineering

Farmers can increase crop yield by controlling the conditions the plants grow in.

Maize is a crop plant.

A variety of maize has been genetically modified (GM) to be resistant to a herbicide.

Explain how growing GM herbicide-resistant maize can produce a larger yield than growing non-GM maize.

Explain how growing a GM herbicide-resistant crop can decrease the biodiversity of animals.

Bees are a type of insect.

The number of insects near a crop can be increased by planting hedgerows.

Increasing the number of bees and other insects increases crop yield.

Suggest two reasons why increasing the number of insects can increase crop yield.

Hedgerows provide habitats for insects.

Give one reason why increasing hedgerow habitats increases insect numbers.

Some farmland contains areas of peat.

When peat is dug up:

• the oxygen levels in the peat increase

• the peat decays quickly.

Explain why increasing the level of oxygen in peat contributes to climate change.

Potatoes are a food crop.

Potato plants are classified as eukaryota.

What type of classification group is eukaryota?

Tick (✓) one box.

Potato plants can reproduce by asexual reproduction.

Which statement is true for asexual reproduction?

Tick (✓) one box.

Flowers of potato plants contain gametes for sexual reproduction.

How is a gamete different from other cells in a potato plant?

Tick (✓) one box.

Plants in the same genus as potatoes have been studied by scientists.

Describe one way a new plant species could be identified as being in the same genus as potatoes.

Scientists have collected and stored seeds from species in the same genus as potatoes.

In the future, these seeds may be used for genetic modification of potato plants.

Genetically modified potato plants could help supply food to the human population as the climate changes.

Explain why genetic modification of crop plants may be important for the human population to survive climate change.

Potatoes are a food crop.

Potato plants are classified as eukaryota.

What type of classification group is eukaryota?

Tick () one box.

Potato plants can reproduce by asexual reproduction.

Which statement is true for asexual reproduction?

Tick () one box.

Flowers of potato plants contain gametes for sexual reproduction.

How is a gamete different from other cells in a potato plant?

Tick () one box.

Plants in the same genus as potatoes have been studied by scientists.

Describe one way a new plant species could be identified as being in the same genus as potatoes.

Scientists have collected and stored seeds from species in the same genus as potatoes.

In the future, these seeds may be used for genetic modification of potato plants.

Genetically modified potato plants could help supply food to the human population as the climate changes.

Explain why genetic modification of crop plants may be important for the human population to survive climate change.

Salmon are fish. A species of salmon has the binomial name Oncorhynchus keta.

Table 3 shows the classification for this species of salmon. Complete Table 3. Choose answers from the box.

Figure 5 shows sea lice attached to the skin of a salmon.

Sea lice are small animals that feed on the skin and blood of salmon. On a salmon farm, the salmon are fed with food made from soya plants.

Which food chain represents the salmon, sea lice and soya plants? Tick (✓) one box.

What do the arrows in a food chain represent? Tick (✓) one box.

Some salmon are more resistant than other salmon to sea lice infections. Salmon farmers selectively breed salmon.

Salmon farmers select salmon that are most resistant to sea lice and breed these salmon together. What is the next stage in selectively breeding salmon that are resistant to sea lice? Tick (✓) one box.

When is the process of selective breeding finished? Tick (✓) one box.

Salmon that do not have sea lice are more profitable for the salmon farmer. Suggest one reason why.

What is a disadvantage of selectively breeding salmon? Tick (✓) one box.

Other fish farmers have produced genetically modified (GM) salmon.

GM salmon grow large enough to sell in 18 months. Non-GM salmon grow large enough to sell in 3 years. GM salmon need 25% less food than non-GM salmon to get to the same size.

Suggest two advantages of farming GM salmon instead of farming non-GM salmon.

GM salmon are often farmed a long distance from where wild, non-GM salmon live. What is an advantage of farming GM salmon a long distance from where wild salmon live? Tick (✓) one box.

This question is about genetics.

Crop plants are genetically modified (GM) for useful characteristics. Which useful characteristic are crops genetically modified for? Tick (✓) one box.

What is one concern about GM crops? Tick (✓) one box.

Some inherited disorders are caused by a faulty piece of DNA.

What is the name of a piece of DNA that codes for a characteristic?

DNA contains a code for making substances in the cell. What type of substance is made using the DNA code? Tick (✓) one box.

Cystic fibrosis (CF) is an inherited disorder. The allele for having CF is recessive (h). The allele for not having CF is dominant (H).

What is a recessive allele? Tick (✓) one box.

A man and a woman do not have CF. The man has the alleles Hh.

What word describes the alleles of the man? Tick (✓) one box.

The man and the woman want to have a child. Complete Figure 1 to show the possible genotypes of the child. Draw a ring around the genotype of a child who will have CF.

What is the chance that a child of the man and the woman will have CF? Tick (✓) one box.

The woman is pregnant. The woman can have embryo screening to find out if the child will have CF. Suggest one reason why the woman might not want to have embryo screening.

Vectors are used in the process of genetic engineering. Which two statements are correct? Tick (✓) two boxes.

Scientists have genetically engineered a variety of wheat to be resistant to herbicides. The herbicide resistant variety of wheat will give a higher yield than the non-herbicide resistant variety. Explain why.

Give two examples of genetic engineering in use today. Do not refer to herbicide resistance in your answer.

Scientists working on the ‘Human Genome Project’ have now mapped the entire genetic code of humans. Explain one way this could be important for people in the future.

Read the following.

The IR8 variety of rice was produced by selective breeding. Describe the steps the scientists would have taken to produce IR8

The IRRI has now developed several new varieties of genetically modified (GM) rice plants. Some people in India agree and some people disagree with GM varieties of rice being grown. Explain why.

Many people eat shellfish called oysters. An oyster has 20 chromosomes in each body cell.

Which arrangement of chromosomes will a male oyster have in each body cell? Tick one box.

Oyster gametes only contain half the amount of DNA compared to a normal oyster body cell. Describe the type of cell division that produces gametes.

Biologists have discovered a way to produce oysters that have three sets of chromosomes (triploid) instead of the usual two sets (diploid). The triploid oysters cannot reproduce and so they grow more quickly. Diploid oysters do not taste good in the reproductive season. Triploid oysters taste good all year. Figure 5 shows the chromosomes in a diploid cell and in a triploid cell. Only two sets of chromosomes are shown.

Suggest why the triploid oysters are not able to reproduce.

Explain why the triploid oysters grow more quickly than the diploid oysters.

The population of diploid oysters growing in the wild has reduced by over 80% in the last 20 years. Suggest two environmental factors which may be causing this reduction. Give a reason why each factor may be causing the reduction in the population.

Oyster farmers grow the triploid oysters from young seed oysters. The production of seed oysters involves the use of a chemical called cytochalasin B. Cytochalasin B has been shown to cause cancer in mice. Evaluate the production of triploid oysters for supermarkets and restaurants.