Topic 9 - Selective Breeding

Question 1

why are organisms selectively bred?

Answer 1

to develop the best features

Question 2

what is the basic process involved in selective breeding?

Answer 2

1. select which organisms have the best characteristics from your existing stock
2. breed them
3. select the best of the offspring and breed them
4. continue this over several generations

Question 3

how can selective breeding increase meat yield of cows?

Answer 3

1. select cows with characteristics that will increase meat yield and breed
2. select the offspring with the best characteristics and breed them
3. continue over several generations

Question 4

why are cows and bulls often artificially inseminated?

Answer 4

mating them naturally is very difficult. its safer for the cow, and semen is much quicker and cheaper to transport compared to bulls. the semen can also be stored after the bull has died.

Question 5

how can selective breeding increase the number of offspring in sheep?

Answer 5

female sheep who produce large numbers of offspring are bred with rams whose mothers had large numbers of offspring

Question 6

how can selective breeding increase crop yield?

Answer 6

selective breeding can be used to combine two desirable characteristics
tall wheat plants (good grain yield but easily damaged) and dwarf wheat plants (bad grain yield but more resistant to damage) are cross-bred, resulting in a new variety with the favourable characteristics from each