3.2 Plant and animal breeding Flashcards
Breeders develop crops and animals with..
Higher food yields, higher nutritional values, pest and disease resistance and ability to thrive in particular
environmental conditions
Plant field trials
Are carried out in a range of environments to compare the performance of different cultivars or treatments and to evaluate GM crops
What has to be taken into account when designing field trials?
The selection of treatments, the
number of replicates and the randomisation of treatments
The selection of treatments..
To ensure valid comparisons
The number of replicates..
To take account of the variability within the sample
The randomisation of treatments..
To eliminate bias when measuring treatment effects
Describe inbreeding
Selected related plants or animals are bred for several generations until the population breeds true to the desired type due to the elimination of heterozygotes
How do you analyse the patterns of inheritance in inbreeding
Monohybrid crosses
What is the result of inbreeding
A result of inbreeding can be an increase in the frequency of individuals who are homozygous for recessive deleterious alleles. These individuals will do less well at surviving to reproduce. This results in inbreeding depression
In animals..
Individuals from different breeds may produce a new crossbreed
population with improved characteristics
The two..
Parent breeds can be maintained to
produce more crossbred animals showing the improved characteristic
How can new alleles be introduced to a plant or animal lines?
By crossing a cultivar or breed with an
individual with a different, desired genotype
How do you create a relatively uniform heterozygous crop?
In plants, F1 hybrids, produced by the crossing of two different inbred lines
F1 hybrids often have..
Increased vigour and yield. Plants with increased vigour may have increased disease resistance or
increased growth rate
Why are F1 hybrids not usually bred together?
The F2 produced shows too much variation
