Wheat rust is a fungal disease known as the “polio of agriculture”.

In 2014, wheat rust spread from Africa to Asia and Europe, and destroyed countless wheat crops.

Scientists were concerned about the impact of wheat rust on global food security.

Explain how the food security of wheat could be improved:

• by using fungicide
• by using selective breeding

Give two advantages of cloning resistant wheat plants rather than selectively breeding them to produce offspring that is resistant to the fungus.

Some dogs are selectively bred so that they do not cause allergic reactions in people.

Suggest two other reasons why people might selectively breed dogs.

Selective breeding can lead to inbreeding.

State one problem inbreeding might cause.

Some dogs are selectively bred for their small size.

Describe how a breeder might use selective breeding to produce a dog that is very small.

The human population on Earth has increased significantly, leading to food shortages.

The growth of drought-resistant crops could allow people to produce more food and avoid famine in certain parts of the world.

Describe how drought-resistant crop plants can be produced.

Give two other examples of characteristics that are desirable in crops and can be selectively bred for.

Which of the following is a common feature of both natural selection, and selective breeding?

Farmers selectively breed pigs to produce larger animals.

Explain how farmers can use selective breeding to produce larger pigs.

Describe one benefit and one risk of selectively breeding pigs.

A farmer has four breeds of sheep on his farm.

• Balwen sheep can live in cold conditions
• Blue-faced Leicester sheep produce good quality wool
• Polled Dorset have good quality meat
• Friesian sheep make a lot of milk

Which sheep would you cross breed to produce sheep with good wool and good meat?

Which breed(s) of sheep would you breed together in order to produce high amounts of milk?

Describe how a new breed of sheep might be produced by selectively-breeding two other breeds.

Gamekeepers in the 19th century kept mastiffs.

Mastiffs are big, strong dogs, but not very fast. Mastiffs are also friendly.

Gamekeepers had a big problem.

Poachers were entering gamekeepers' land and stealing their birds before shooting season. 

Gamekeepers knew of the existence of the bulldog.

Bulldogs are quick, aggressive but not strong enough to pull the poachers down and hold them until a gamekeeper arrived.

Explain how the gamekeepers used selective breeding to produce a new breed of dog, the bullmastiff.

Selective breeding could cause problems of inbreeding in dogs.

Describe one problem inbreeding causes.

Bananas have been selectively bred to be thinner, sweet, easy to peel, and relatively seedless.

Originally, bananas were not very sweet, had a tough skin and large seeds.

Explain how the process of selective breeding was used to produce the bananas we eat today.

In selective breeding which organisms breed?

Nowadays, 97% of internationally traded bananas come from one single variety, the Cavendish.

The Cavendish banana is threatened by Panama disease, caused by a fungus.

Suggest why eating only one variety of banana may be a problem in the future.

Describe the process of selective breeding to generate goats that produce large quantities of milk and then state and explain one risk of using selective breeding this way.