3.2 Plant and Animal Breeding Flashcards
Why do plants/animals breed?
To improve characteristics to help support sustainable food production
What kind of crops and animals do breeders develop?
Those with higher food yields, higher nutritional values, pest and disease resistance and the ability to thrive in particular environmental conditions
Why are plant field trials carried out in a range of environments?
To compare the performance of different cultivars or treatments and to evaluate GM crops
What needs to be accounted for in field trials?
The selection of treatments, the number of replicates and the randomisation of treatments
What do all the measures account for in a field trial?
Selection- ensures valid comparison
Replicates- variability within the sample
Randomisation- eliminates bias when measuring treatment effects
In inbreeding, selected related plants or animals are bred for several generations until what?
The population breeds true to the desired type due to the elimination of heterozygotes
What are monohybrid crosses used for?
The analysis of patterns of inheritance in inbreeding
What is inbreeding depression?
An increase in the frequency of individuals who are homozygous for recessive deleterious alleles. They do less well at surviving to reproduce.
How can new alleles be introduced to plant and animal lines?
By crossing a cultivar or breed with an individual with a different desired genotype
How are F1 Hybrids produced in plants?
By the crossing of two different inbred lines, creating a relatively uniform heterozygous crop
F1 Hybrids often have increased vigour and yield. How does this benefit plants?
May have increased disease resistance or increased growth rate
Why are F1 hybrids not usually bred together?
The F2 produced shows too much variation
How can organisms with desirable genes be identified and used in breeding programmes?
Due to genome sequencing
How are GM plants with improved characteristics made?
Single genes for desirable characteristics can be inserted into the genomes of crop plants
What do Bt toxin and glyphosate resistance genes do for plant breeding?
Bt- pest resistant
Glyphosate- herbicide tolerance
