Genetic engineering

Fruit flies are small insects.

Figure 6 shows a fruit fly.

Fruit flies:

are easy to keep in containers

have a short time between one generation and the next generation

are used to study evolution.

Why is it easier to study evolution in fruit flies rather than in humans?

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Fruit flies do not produce many offspring.

Fruit flies show more different characteristics than humans.

Many generations of fruit flies can be produced in less time.

The environment that the fruit flies are in can be controlled.

The fruit flies can fly between different places.

A scientist studied the length of fruit fly wings.

The scientist used selective breeding to produce a population of fruit flies with longer wings.

The first stages in the selective breeding process were:

Place five female fruit flies with the longest wings in a container.

Add five male fruit flies with the longest wings to the container.

Let these fruit flies breed.

Place the five female offspring with the longest wings in a new container.

Add the five male offspring with the longest wings to the new container.

What is the next stage in the process of selective breeding?

After many generations, the offspring all had long wings.

The scientist stopped selectively breeding the fruit flies.

After a further 15 generations, the fruit flies all had short wings.

Which process may have caused the fruit flies to have short wings?

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Classification

Mitosis

Natural selection

Some fruit flies damage crops.

How can farmers kill fruit flies that damage crops?

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Add fertiliser to the soil.

Place compost around the plants.

Spray crops with pesticide.

One species of fruit fly has been genetically modified (GM) to only produce male offspring.

Scientists can release large numbers of the GM fruit flies where wild fruit flies are damaging crops.

The GM fruit flies will breed with wild fruit flies.

Releasing the GM fruit flies will decrease the population of wild fruit flies.

What is one advantage of releasing the GM fruit flies?

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GM fruit flies look different to wild fruit flies.

Less of the crop is damaged by fruit flies.

Wild fruit flies reproduce at a faster rate.

What is one disadvantage of decreasing the population of wild fruit flies?

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Birds that eat fruit flies will have more food.

Food chains and food webs will be disrupted.

Fruit flies will have different characteristics.

This question is about genetics.

Draw one line from each term to the meaning of the term.

The inheritance of sex in humans is controlled by two chromosomes, X and Y.

Complete Figure 8 to show how sex is inherited.

In 2018 a scientist claimed to have genetically modified two human embryos.

Why is genetic modification of human embryos illegal in most countries?

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Genetic modification technology is too expensive.

Specialist equipment is needed for genetic modification.

The side effects of genetic modification are not known.

The scientist claimed the genetic modification was made to embryos immediately after fertilisation.

Why is genetic modification of embryos more of a concern than genetic modification of body tissues in an adult?

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Genetically modified body tissues are much larger than an embryo.

The genetic modification of an embryo would not affect all the body tissues.

The modified gene in an embryo could be passed on to future offspring.

The scientist claimed that the embryos were genetically modified to be resistant to HIV infection.

Why do some scientists think this use of genetic modification is not necessary?

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HIV infection can be treated with antiretroviral drugs.

Only adults are at risk of HIV infection.

Oral contraceptives reduce the risk of HIV infection.

This question is about genetics.

Explain why different genes are made from different lengths of DNA.

Describe why the human population produces approximately 50% female and 50% male babies.

In 2018, a scientist claimed to have genetically modified two human embryos.

Suggest why genetic modification of human embryos is illegal in most countries.

The scientist claimed that the embryos were genetically modified to have a faulty CCR5 gene.

The CCR5 gene codes for a protein that allows HIV to enter cells.

The genetic modification may have caused the embryos to be protected against AIDS.

Suggest how the embryos were genetically modified to make the CCR5 gene faulty.

Suggest what type of cell has the CCR5 protein in its cell membrane.

What type of drug is used to treat HIV?

Fatty material can build up in coronary arteries.

The flow of blood through coronary arteries may be reduced.

Which organ contains coronary arteries?

There are different treatments for coronary diseases.

Draw one line from each treatment to how the treatment works.

Some medical drugs can be produced using genetically modified (GM) bacteria.

How are GM bacteria produced?

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All genes are removed from the bacteria.

Bacteria are grown in a solution of the drug.

Genes are transferred into the bacteria.

What is one benefit of producing drugs using GM bacteria?

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Large quantities of the drug can be produced.

Non-GM bacteria live longer than GM bacteria.

The GM bacteria that produce the drug are very infectious.

Scientists are investigating the production of organs from GM animals for transplanting into humans.

What is an advantage of using organs from GM animals compared with using organs from human donors?

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Organs from GM animals are less likely to be rejected by the human immune system.

Organs from GM animals are not likely to function correctly.

There are more human donors than the number of people who need a transplant.

Suggest one reason why some people disagree with the use of GM animals.

Organisms have been genetically modified (GM) for many reasons.

What has been genetically modified to produce a hormone that reduces blood glucose concentration?

Tick (✓) one box.

Algae

Bacteria

Viruses

Scientists are researching the production of GM pigs.

Organs from GM pigs could be transplanted into humans.

What is one advantage of using organs from GM pigs instead of using organs from human donors?

Describe how a human gene could be used to genetically modify a pig embryo.

Farmers produce cotton from cotton plants.

Figure 7 shows a cotton plant.

Insects feed on cotton plants.

Cotton plants have been genetically modified to produce a pesticide that kills insects.

Give one advantage to a farmer of growing cotton plants that are able to kill insects.

Bollworms are insects that eat cotton plants.

Most bollworms are killed if they eat the GM cotton.

Some bollworms have a gene that allows the bollworm to eat GM cotton and survive.

The allele for being killed by eating GM cotton is dominant.

The allele for being able to eat GM cotton and survive is recessive.

Two bollworms mate. Both bollworms would be killed by eating GM cotton.

80 offspring are produced.

Some offspring are able to eat GM cotton and survive.

Predict how many of the 80 offspring are likely to be able to eat GM cotton and survive.

You should:

draw a Punnett square diagram

identify the genotypes of the two parent bollworms

identify the phenotype of each offspring genotype

use the symbols: B = dominant allele b = recessive allele

Predicted number of offspring that will be able to eat GM cotton and survive = __________________

The allele in bollworms for being able to eat GM cotton and survive is recessive.

A bollworm may evolve that has a new dominant allele that allows the bollworm to eat GM cotton and survive.

Explain how a new dominant allele emerging would cause a greater problem than the recessive allele that already exists.

This question is about genetics.

Figure 3 shows the chromosomes of a man.

What evidence is there that the person is male?

Use Figure 3.

A combination of genes and the environment affect how tall a person is.

Give one other human characteristic that is affected by genes and the environment.

Do not refer to height in your answer.

Cystic fibrosis is an inherited disorder that affects the lungs.

Suggest one symptom caused by damaged lungs.

The allele for having cystic fibrosis is recessive, r.

The allele for not having cystic fibrosis is dominant, R.

What is the genotype of a person with cystic fibrosis?

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RR Rr rr

A man has the genotype RR.

Which word describes the genotype RR ?

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Characteristic

Homozygous

Phenotype

A woman has a child with a man.

Complete Figure 4 to show the possible genotypes of the child.

Figure 4

What is the chance of the child having cystic fibrosis?

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0% 25% 50% 75%

Drugs are being developed to treat cystic fibrosis in humans.

The drugs are tested before being used to treat patients.

Give two reasons why drugs are tested.

The drugs are tested on sheep that have been genetically modified (GM) to develop the symptoms of cystic fibrosis.

Give one ethical argument against the production of sheep with the symptoms of cystic fibrosis.

Do not refer to religion in your answer.

This question is about inheritance.

Complete Figure 8 to show why the probability of a child being a male is 0.5

Figure 8

Cystic fibrosis is an inherited disorder.

The allele for cystic fibrosis is recessive, r.

The dominant allele is R.

A man and a woman plan to have a child.

The man and the woman are both heterozygous for cystic fibrosis.

Determine the probability that the child will be a male with cystic fibrosis.

You should:

draw a Punnett square diagram identify which of the offspring genotypes will have cystic fibrosis.

Some sheep have been genetically modified to develop the symptoms of cystic fibrosis.

Give one ethical argument for the production of sheep with the symptoms of cystic fibrosis.

Do not refer to religion in your answer.

Give one ethical argument against the production of sheep with the symptoms of cystic fibrosis.

Do not refer to religion in your answer.

The sheep were genetically modified as embryos.

Describe the stages involved in producing a genetically modified sheep that shows symptoms of cystic fibrosis.

Figure 4 shows a mosquito on human skin.

Malaria is a communicable disease.

Mosquitos can transmit malaria when they bite.

What is a communicable disease?

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Humans have adaptations to defend the body against pathogens.

Draw one line from each body part to the adaptation that defends against pathogens.

What type of chemical is used to kill mosquitos?

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Scientists are trying to reduce the number of people developing malaria by using genetically modified (GM) mosquitos.

Mosquitos have 6 chromosomes in each normal body cell.

How many chromosomes are in each egg cell from a mosquito?

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Which statement describes genetic modification?

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GM mosquitos can be produced in large numbers in laboratories.

These GM mosquitos can be released to reduce the population of wild mosquitos.

What is one advantage of using GM technology to reduce the population of wild mosquitos?

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Cystic fibrosis is an inherited condition.

The allele for having cystic fibrosis is recessive, r.

The dominant allele is R.

A person who has the genotype Rr is a ‘carrier’ of cystic fibrosis.

Carriers do not have symptoms of cystic fibrosis.

What scientific term describes the carrier’s genotype, Rr ?

Figure 5 shows the inheritance of cystic fibrosis in one family.

Person 6 and person 7 plan to have another child.

Draw a Punnett square diagram to show the probability of the child having cystic fibrosis.

Identify the genotypes of any offspring with cystic fibrosis.

Use Figure 5.

Mucus is produced in the breathing system.

In people with cystic fibrosis the mucus is thicker than the mucus produced in an unaffected person.

Explain why a person with cystic fibrosis has an increased risk of lung infections.

Some medical products are produced by genetically modified (GM) organisms.

Hamsters are small mammals.

GM hamster cells are used to produce drugs to treat some human genetic disorders.

Describe how a human allele can be transferred into the genome of a hamster cell.

Name a medical product that can be produced by GM bacteria.

Give the name of the disorder the product is used to treat.

Bananas from wild banana plants are not eaten by humans.

Edible banana plants are grown commercially.

Humans can eat bananas from edible banana plants because they do not contain seeds.

The edible banana plant evolved from the wild banana plant.

Figure 12 shows how scientists think the edible banana plant may have evolved.

What is process X in Figure 12 ?

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Explain why the edible banana plant cannot produce gametes.

Cloning is used to reproduce edible banana plants.

The cloned cells divide by mitosis.

Describe the process of mitosis.

Banana plants can become infected by the TR4 fungus.

The fungus enters the plant through the roots and grows within the xylem vessels.

The xylem vessels become blocked and the leaves turn yellow.

Describe why blockage of the xylem vessels causes the leaves to turn yellow.

TR4 fungus is a threat to the global banana industry.

Some wild banana plants have a gene for resistance to the TR4 fungus.

What could scientists do to protect edible banana plants from the TR4 fungus?

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