Genetic engineering

All living cells contain enzymes.

Describe the role of enzymes in cells.

The table lists some enzymes, where they are produced and their function. Complete the table by giving the missing information.

Explain how changes in temperature affect the activity of an enzyme.

Genetically modified (GM) crops have been developed over the last 30 years.

Explain what is meant by the term genetically modified.

Farmers have been growing GM soybean and corn for a number of years. The table shows data for soybean and corn grown in the USA from 1996 to 2014. It shows the percentage of each crop that is GM.

Plot a line graph of the data on the grid. Use a ruler to join the points with straight lines.

Describe the changes in the use of GM soybean and corn from 1996 to 2014.

Herbicides are chemicals that kill plants. Crops can be genetically modified to be herbicide resistant. Suggest why farmers may want to grow crops that are herbicide resistant.

Farmers also grow GM crops that are resistant to other factors. Name one of these factors.

Selective breeding is another way of improving crop production. Describe how selective breeding could be used to improve seed size in wheat.

Read the passage below. Use the information in the passage and your own knowledge to answer the questions that follow. Omega-3 Excess lipids (fats and oils) in the human diet can increase the risk of health problems such as obesity, heart disease and strokes. However, a balanced diet needs to contain fats and oils because they are needed in the human body for many important functions. Scientists have recently discovered that a type of fatty acid contained in oils can also benefit human health. The fatty acids that provide benefits to human health are called omega-3 fatty acids. A diet rich in these fatty acids is thought to lower blood pressure and reduce the risk of heart disease. Fish oils are known to contain high levels of omega-3 fatty acids. Fish farmers know that the fish they produce are of more value to the consumer if they contain oils rich in omega-3. As a result, about 80% of the fish oil produced globally from the oceans is used as food in fish farms. Small fish called anchovies live in our oceans. They eat microscopic plants called plankton that contain high levels of omega-3. As the anchovies grow, they also contain high levels of omega-3 in their oil. Fishing boats catch billions of these small fish, that are then ground up to be fed to bigger fish such as salmon, on fish farms. Fish farms consume vast quantities of anchovies. The increase in the number of fish farms is one reason why wild fish stocks of anchovies are declining. It takes about 5 kg of anchovies to produce 1 kg of farmed salmon. The high cost of this source of fish oil has encouraged fish farmers to use less, so the fish they produce contain lower levels of omega-3 in their oil, which is not good for human health. Recently, scientists have discovered another way to obtain high levels of omega-3 to feed to fish on fish farms. The scientists genetically modified a plant called Camelina to produce seeds containing omega-3 fatty acids. This discovery will enable these seeds to be fed to salmon in fish farms and could reduce overfishing of the oceans.

Suggest how excess lipids (fats and oils) increase the risk of heart disease (lines 1 and 2).

Fats and oils are large, insoluble molecules needed in a balanced diet (lines 2 and 3). Give the names of two small, soluble molecules needed in a balanced diet.

State a function of lipid in the human body.

Fatty acids are one component of a lipid molecule. Name another component.

Use the information in the passage to draw a food chain that includes anchovies (lines 13 to 17).

Suggest why wild fish stocks are declining.

Explain why 5 kg of anchovies only produce 1 kg of farmed salmon (line 20).

The genetic modification of Camelina plants involves the use of enzymes and a vector (lines 24 and 25).

Explain how enzymes are used in genetic modification.

Describe the role of a named vector in genetic modification.

What is meant by the term transgenic organism ?

Give an example of a current or potential use of a transgenic animal.

When a transgenic animal has been produced, it can then be cloned. Explain the benefits of cloning this animal.

Every effort has been made to contact copyright holders to obtain their permission for the use of copyright material. Pearson Education Ltd. will, if notified, be happy to rectify any errors or omissions and include any such rectifications in future editions.

The fungus Fusarium venenatum is grown in a fermenter to make a food product called mycoprotein.

Name the molecule that a fungus uses to store carbohydrate.

Name the thread-like structures that make up the mycelium of a fungus.

Mycoprotein contains low levels of fats and is high in protein. Suggest the benefits of each of these to a human diet.

Food production can be increased by using genetically modified plants that are resistant to disease. Explain how enzymes can be used to genetically modify plants.

An investigation was carried out to find out the effect of a growth hormone on milk production. Groups of cows were given different masses of a growth hormone. The volume of milk the cows produced was then measured. The graph shows the results.

mass of growth hormone given per day

How much growth hormone should have been given to the control group?

Describe the effect of growth hormone on milk production.

Farmers want to make reliable comparisons about the effect of different doses of growth hormone.

What was done in this investigation to make the results reliable?

Many variables that affect milk production need to be kept the same for each group of cows. This allows a valid comparison to be made between each group. Give two variables that need to be kept the same.

Growth hormone is a protein. It might be present in the milk produced by the cows and then be consumed by humans. Some people are worried that this may harm humans. Other people say that this is not a problem for two reasons. Firstly, the milk is pasteurised (heated to high temperatures). Secondly, the growth hormone is destroyed in the human stomach.

Suggest what happens to the growth hormone when milk is pasteurised.

Describe how the growth hormone could be destroyed in the stomach.

The growth hormone used in this investigation was obtained from genetically modified bacteria. Describe how bacteria can be genetically modified and used to produce growth hormone.

Explain what is meant by the term transgenic organism.

Give one example of the use of transgenic organisms.

Describe the stages by which a bacterium can be genetically modified to produce large amounts of a named human protein.

Describe the stages that are used to genetically modify a bacterium that is able to manufacture human growth hormone.

BST is a hormone that increases milk yield in cows.

Explain what is meant by the term hormone.

In some countries BST from genetically modified bacteria has been injected into cows to improve milk production. In other countries selective breeding has been used to improve milk production. Describe how selective breeding could be used to increase milk production.