Selective Breeding Flashcards
1
Q
How is selective breeding in mammals beneficial
A
- maximum yield of meat, milk, grain etc
- good health and disease resistance
- other qualities such as temperament, speed, fertility, good mothering skills etc
- plants = attractive flowers, nice smell etc
2
Q
Process of selective breeding
A
- the two animals with desired characteristics are selected
- breed them with each other
- select the best of off spring and breed them together
- continue process of several generations and the desirable trait gets stronger
- in farming this will give the farmer gradually better and better yields
3
Q
How can selective breeding increase the productivity of cows
A
- cows can be selectively bred to produce offspring with higher meat yield
- animals with characteristics that will increase meat yield (largest cows and bulls) are selected and mate together
- the offspring with the best characteristics mate together and process is repeated over several generations to gradually increase meat yield
- mating cows and bulls naturally can be difficult som artificial insemination is often used
4
Q
How can selective breeding increase the number of offspring in sheep?
A
- female sheep who produce large numbers of offspring are bred with rams whose mothers had large numbers of offspring
- the characteristic of having large numbers of offspring is passed on in the next generation
5
Q
How can selective breeding increase crop yield?
A
- used to combine two desired characteristics
- tall wheat have a good grains yield but are easily damaged by rain and wind. Dwarf wheat plants can resist wind and rain but have low grain yield
- these two types of wheat plants were cross-bred and the best resulting plants were cross-bred
- this resulted in a new variety of wheat combining good characteristics of revisiting bad weather and high grain yield
6
Q
Why is artificial insemination used for the selective breeding of cows?
A
- it can be safer for the cow and also much quicker and cheaper to transport semen than bulls for artifice, inseminiation
- the semen can be used to impregnate multiple cows and can be stored after the bull has died
