Selective breeding and human food security | Exit Quiz | Oak National Academy

True or false? Selective breeding is when humans choose which individuals to breed based on their characteristics.

• true

• false

Answer explanation

It takes many generations of selective breeding to establish the desired characteristics in a “breed” as the process of fertilisation is random. Genetic modification can be used to speed up the process.

Put the steps in the correct order to describe the process of selective breeding.

• Repeat for many generations.

• Select two individuals with the desired characteristic.

• Breed them together.

• From the offspring produced, choose individuals with the desired characteristic.

• Breed these offspring together.

Answer explanation

The process takes many generations to have an effect and essentially never stops.

Food security is a measure of the quality and quantity of food available to humans. Why is this increasingly important globally?

• Humans are fussy eaters.

• The human population is continuously increasing.

• There are thousands of edible plants and animals.

• In the UK there is an increase in obesity.

Answer explanation

The growth of the human population and the unequal distribution of wealth and resources means much of the world’s population can be at risk of malnutrition or worse.

Although there are thousands of edible plants worldwide, farmers and plant breeders have selectively bred only a few of these. Most of our energy comes from just three plants: corn, wheat and ___.

Answer explanation

Relying so heavily on just these three plants may leave us vulnerable to a new plant disease or pest that seriously affects them.

During the green revolution, Norman Borlaug produced modern wheat crop plants by breeding which two varieties of wheat?

• Dwarf thin stemmed with tall small grained.

• Dwarf thin stemmed with tall big grained.

• Dwarf thick stemmed with tall small grained.

• Dwarf thick stemmed with tall big grained.

Answer explanation

Producing high yielding, lots of grain, dwarf plants allowed the production of more wheat per hectare and so the feeding of more people from the same area of land.

There are many desirable characteristics that selective breeders have looked for to produce better crop plants for food. Which is not one of these desirable characteristics?

• crop mass

• disease resistance

• pleasing appearance

• taste

Answer explanation

Many breeds of domesticated animals, e.g. dogs, are bred for appearance but this is not the case for crop plants.