3.2 Plant and Animal Breeding Flashcards
Give an example of a desirable plant characteristic that breeders would select for
Higher Yielding
Larger Fruits
Drought Resistance
Give an example of a desirable animal characteristic that the breeders would select for
Higher Nutritional Value
Higher Fertility Rate
What is an ‘allele’?
An allele is different forms of the same gene
Why is plant/animal hereditary material manipulated?
To improve plant crops
To improve animal stock
To support sustainable food production
What is selective breeding?
The process by which new varieties of species are produced due to the deliberate breeding of individuals
What is an advantage of inbreeding?
Eliminate heterozygosity
Will breed true to type
Define ‘Inbreeding Depression’
The gradual build up of homozygous recessive alleles
How can outbreeding be used to avoid inbreeding depression
Crossing organisms with unrelated individuals will help regain genetic diversity
Why are plant field trials carried out?
- compare performance of different cultivars
- evaluate GM crops
What are the considerations when designing a field trial?
<ol> <li>Selection of treatments</li> <li>Randomisation of treatments</li> <li>Replication of treatments</li> </ol>
Why is the selection of treatments considered when designing a field trial?
To ensure fair comparisons
Why is the randomisation of treatments considered when designing a field trial?
To eliminate bias when measuring treatment effects
Why is more than one field trial conducted?
To take account of variability and decrease the effect of A typical results
What is a field trial?
An investigation set up to compare the performance of two different cultivars in the same environmental conditions
What is outbreeding?
Outbreeding is where two unrelated members of species are breeded together
Give an example of a plant that is a natural inbreeders
Peas, wheat, rice
What is Hybrid Vigour?
Hybrid Vigour is the result of two parents who have desirable characteristics breeded together. It involves the F1 generation having increased vigour, yield and fertility.
Why are the F2 generation after the hybrid generation not as usual?
The F2 generation will be too genetically diverse and will lack improved characteristics
What is required to maintain the hybrid vigour seen in the F1 generation of two crossed animals with desirable characteristics
Backcrossing
Parent breeds maintained
How can new alleles be introduced to plant cultivars?
Crossing a cultivar with an individual with a different desirable genotype
What are test crosses used for?
To identify unwanted individuals with heterozygous recessive alleles
What is genome sequencing?
Identification of all nucleotide bases for an entire genome of an organism’s
How can genetic transformation be used in breeding programs?
A gene can be inserted into a genome
This organism can then be used in breeding programs
Why is backcrossing required?
To eliminate unwanted genetic material whilst maintaining the desired characteristics
