Selective Breeding

Question 1

What is selective breeding and why is it used?

Answer 1

When humans breed other animals and plants for particular characteristics. Plant scientists use selective breeding to help to feed our increasing population.

Question 2

How does selective breeding work?

Answer 2

• to produce the highest yield, farmers choose their best plants or animals to breed. The offspring are likely to share the favourable characteristic of the parents
• selective breeding can also produce crops with high resistance to pests and diseases

Question 3

How does a farmer selectively breed organisms?

Answer 3

1) decide which characteristics are favourable
2) select parents with the highest levels of the characteristics
3) breed the individuals
4) select the best offsprings and breed again
5) repeat over generations until all offsprings share the common favourable characteristics

Question 4

How has selective breeding changed wheat?

Answer 4

Wild | Modern

• small eats with few seeds | large ears with many seeds
• brittle stale that eats often fall off | stronger stalks that ears stay on
• ears ripen at different times | ears ripen at the same time
• stalks grow to different highest | stalks grow to the same height

Question 5

What are the disadvantages of selective breeding?

Answer 5

• reduces number of alleles of a species which reduces variation. If a new disease occurs, there may not be an organism with the allele for resistance of this gene. His may cause it to go extinct
• increases the chance of inheriting a genetic disease