Genetic engineering

Which of these is an example of genetic engineering ?

A Captive breeding programmes for endangered species

B Farmers applying pesticides on their crops

C Scientists developing crops that are drought resistant

D Selecting pigs with high quality meat to breed together

The picture shows the plant pathogen that causes powdery mildew.

Describe how powdery mildew is spread from one plant to another.

Powdery mildew reduces the efficiency of chloroplasts.

Explain how this might reduce the rate of respiration in a plant.

Plants resistant to powdery mildew are developed by genetic engineering.

Complete the sentences about genetic engineering.

The gene for resistance is cut out of DNA using a........ enzyme.

The gene is then joined to bacterial DNA using a........ enzyme.

To find out if the bacteria contain the gene, scientists use........

Explain why the process of cutting the DNA is prevented by high temperatures.

Use your knowledge of enzymes.

Powdery mildew can be controlled using chemicals.

Producing plants resistant to powdery mildew is better for biodiversity compared to using chemicals.

Suggest two reasons why.

Which sub-cellular structure from a prokaryotic cell is used in genetic engineering?

A Mitochondrion

B Nucleus

C Plasmid

D Ribosome

There are practical and ethical issues when using gene therapy to treat people.

Which statement is only a practical consideration with no ethical issues?

A Choosing which person should benefit from the treatment.

B How to insert the modified allele into a target cell.

C Religious beliefs of the patient.

D Who should pay for the treatment.

What is the function of restriction enzymes in genetic engineering?

A To act as a vector and carry the DNA into the host.

B To cut the required gene from the DNA.

C To identify which cells have taken up the gene.

D To stick the gene into the DNA of the host.

The diagram shows some crops that have been developed from a wild mustard plant.

The cauliflower crops grown today have taken many years to develop.

Name the process used by humans to develop cauliflower plants from wild mustard plants.

Put a tick (✓) next to the correct answer.

Some bacteria have genes which mean that they can produce a natural insecticide. Scientists have produced cauliflowers that contain these genes. This means the cauliflowers can now make their own natural insecticide.

What is modified inside the cauliflower so that it has the genes?

Suggest one reason for and one reason against producing cauliflowers with these genes.

Scientists can now treat blood disorders using gene therapy. To do this they need to obtain blood stem cells.

The blood stem cells are then modified before being placed into the patient.

Complete these sentences to explain the benefits of using modified stem cells.

The stem cells can be modified to stop the........ blood cells of the immune system detecting the stem cells.

This will reduce the chance of........

Scientists that genetically engineer bacteria need to identify those bacteria that have taken up the modified plasmid.

What is used to identify bacteria that have taken up the modified plasmid?

A Antibiotic resistant genes

B Ligases

C Restriction enzymes

D Vectors

The cornea is a part at the front of the eye that allows in light.

The cornea can be damaged by injury or disease. Treatment often requires a local anaesthetic. Local anaesthetics stop nerve impulses passing along the sensory neurone.

Use your knowledge of the structure of a reflex arc to explain why a person would not feel pain.

Pregnancy can affect the response of neurones to local anaesthetics.

The graph shows the effect of a local anaesthetic on nerve activity in women.

Time following local anaesthetic injection (minutes)

Look at the data over the first 10 minutes after injection.

Calculate the percentage decrease in nerve activity after 10 minutes when pregnant compared to not being pregnant.

The data in the graph has range bars plotted. These give the highest and lowest values at each point.

Why is this an improvement when presenting this data?

Explain why stem cells taken from embryos are more suitable than those from adult bone marrow.

* Scientists can use embryo stem cell technology for treating damage to the cornea to restore vision.

Read the information in the box.

• Corneal cells are transparent to allow light to pass through.

• Corneal tissue does not have blood vessels in order to remain transparent.

• Corneal transplants from donor tissue are one way to restore vision after damage to the cornea.

• Corneal transplants are at risk of tissue rejection when blood vessels develop in the cornea.

• Scientists are able to genetically engineer donor corneal cells to prevent new blood vessel formation following transplantation.

• The genetically engineered cells produce a protein which prevents the formation of blood vessels.

Describe the main steps involved in genetically engineering donor corneal cells and identify any improvements and risks from this type of treatment.

Scientists have used genetically engineered bacteria to produce the human hormone insulin.

Describe the main steps in the process of genetic engineering.

Insulin may be used to treat type 2 diabetes.

Describe the interaction between type 2 diabetes and nutrition.

The human genome has been mapped.

Discuss how this could help with the future treatment of type 2 diabetes.

Complete the sentence about cancer.

Cancer is the result of changes in cells that lead to uncontrolled........ and

........

*(b) Treatment of lung cancer can involve surgery and painful chemotherapy. Survival rates for lung cancer are low.

Replication of damaged DNA can lead to cancer. A gene called p53 prevents the replication of damaged DNA. Lung cancer and faults in the p53 gene are linked.

Gene therapy involves replacing faulty genes.

Explain why gene therapy could be used to treat lung cancer and discuss the issues involved in using this type of treatment.

HIV is a virus that causes AIDS.

HIV infects human cells by inserting genes into the cells. The human cells then copy the genes.

In which part of a human cell are HIV genes copied?

chloroplast cytoplasm mitochondria nucleus

In the laboratory, scientists have used gene technology to completely remove HIV genes from infected cells.

Explain how removing HIV genes could affect the spread of HIV.

Suggest why some people are concerned about the use of gene technology in HIV treatment.

The Human Genome Project mapped the human genome.

Write down what is meant by the term genome.

Knowledge of the human genome could identify the genes affected by HIV.

Write down two ways knowledge of the human genome could help with the treatment of HIV.

*(d) Some countries have set up centres where a person is counselled and tested for HIV.

The aim is to reduce new infections by 50%.

Describe how HIV is transmitted and how these centres can contribute to reducing the spread of HIV.

HIV invades white blood cells stopping them working.

Describe the role of white blood cells in the defence against disease.

Complete these sentences about the hormone FSH.

FSH is secreted by the........ gland.

FSH causes an........ to mature in the ovary.

FSH stimulates the ovaries to release the hormone........

FSH hormone can be genetically engineered.

The human gene for FSH is transferred into an animal cell.

Look at the diagram of a cell.

The gene is put inside one of the structures labelled in the diagram.

Which structure is the gene put inside?

Choose from A, B, C, or D........

State why the gene is put there.

* Beta carotene is the substance that makes carrots orange. Humans use beta carotene to make vitamin A. Vitamin A is needed for good vision.

‘Golden’ rice is a genetically modified (GM) crop. ‘Golden’ rice is made when the gene for beta carotene is added to rice.

Scientists do not know if the levels of beta carotene in ‘Golden’ rice will have any other effects on people eating the rice.

In some countries many people survive on a diet of mainly rice with no vegetables.

Do you think ‘Golden’ rice should be made to provide food for these people?

Include arguments for and against ‘Golden’ rice in your answer.

Insulin and glucagon are hormones that control blood sugar levels in the body.

The diagram shows interactions between these two hormones.

Complete the diagram to show how insulin and glucagon work together to control blood

sugar levels.

This type of control system is an example of negative feedback.

Explain why.