unit 3 KA2 - plant and animal breeding

Question 1

how does plant and animal breeding help to improve characteristics to support sustainable food production

Answer 1

breeders can develop crops and animals with

• higher food yields,
• higher nutritional values,
• pest and disease resistance
• ability to thrive in particular environmental conditions

Question 2

why are plant field trials carried out in a range of environments

Answer 2

to compare the performance of different cultivars or treatments and to evaluate GM crops

Question 3

what has to be accounted for when designing field trials

Answer 3

• the selection of treatments
• the number of replicates
• the randomization of treatments

Question 4

why do the selection of treatments need to be accounted for when designing field trials

Answer 4

to ensure valid comparisons

Question 5

why do the number of replicates need to be accounted for when designing field trials

Answer 5

to take account of the variability within the sample

Question 6

why does the randomization of treatments need to be accounted for when designing field trials

Answer 6

to eliminate bias when measuring treatments effects

Question 7

what are mono-hybrid crosses used for

Answer 7

analysis of patterns of inheritance in inbreeding

Question 8

what happens in inbreeding

Answer 8

selected related plants or animals are bred for several generations until the population breeds true to the desired type due to the elimination of hetero-zygotes

Question 9

what is a result of inbreeding

Answer 9

• there is an increase in the frequency of individuals who are homozygous for recessive deleterious alleles
• these individuals will do less well at surviving to reproduce
• results in inbreeding depression

Question 10

how can new alleles be introduced to plant and animal lines

Answer 10

by crossing a cultivar or breed with an individual with a different, desired genotype

Question 11

what can cross breeding and F1 hybrids in animals, individuals from different breed produce

Answer 11

a new crossbreed population with improved characteristics

Question 12

why may the two parent breeds be maintained when cross breeding

Answer 12

they can be maintained to produce more crossbred animals showing the improved characteristic

Question 13

what may plants with increased vigor also have

Answer 13

• increased disease resistance

- increased growth rate