3C - Plant and Animal Breeding Flashcards
How do plant and animal breeders improve characteristics in order to support sustainable food production?
Breeders develop crops and animals with higher food yields, higher nutritional values, pest and disease resistance and the ability to thrive in a particular environmental condition.
What is a consequence of inbreeding?
Inbreeding depression occurs as a result of inbreeding because of the increase in the frequency of individuals who are homozygous for recessive deleterious alleles. These individuals will do less well at surviving to reproduce.
In plant breeding what happens when two inbred lines are crossed?
In plants, F1 hybrids, are produced by crossing two different inbred lines. The F1 hybrids produced are a relatively uniform heterozygous crop. These F1 hybrids often have increased vigour and yield. They may also have increased disease resistance or increased growth rate. F1 hybrids are not usually crossed as their offspring show too much variation.
Explain the use of recombinant DNA technology in plant breeding where the Bt toxin is inserted.
The Bt toxin gene can be inserted into plants to make them pest resistant.
What is inbreeding and why is it used by plant and animal breeders?
Inbreeding is where selected related plants or animals are bred for several generations until the population breeds true for the desired type of characteristic(s) due to the elimination of heterozygotes. (These cultivars or breeds can then be used introduce ‘new alleles’ by crossing individuals with different genotypes.)
In animal breeding, what is a ‘new cross-breed’ and how is it produced?
In animals new crossbreed can be produced by mating individuals from different breeds together. The crossbreed population may have improved characteristics. It is important to maintain the two parent breeds in order to produce the same crossbreed animals for future production as crossing the F1 hybrids would show too much variation.
How is genome sequencing important for producing genetically modified plant crops?
Genome sequencing allows the identification of genes in organisms causing desirable characteristics to be identified and then used in breeding programmes. The single genes for the desirable characteristics are inserted into the genome of crop plants, creating genetically-modified plants with improved characteristics. These genetically-modified crop plants can also be used in breeding programmes.
Explain the use of recombinant DNA technology in plant breeding where the glyphosate resistant gene is inserted.
The glyphosate resistance gene can be inserted to cause herbicide tolerance.
