Unit 3 Plant And Animal Breeding Flashcards
Give for desirable Characteristics that might be selected by breeders who are looking to improve a crop plant species
High nutritional value
High yield
Ability to thrive in a certain environment
Disease and pest resistant
What three things are taken into account when designing a field trial
Selection of treatments
Number of experiments
Randomisation of treatments
What is selection of treatments
To make a fair comparison for example different volumes of fertiliser or sizes of plots
What is randomisation of treatments
Randomisation of treatments is so that all plants get a range of difference so that there isn’t any bias
What is inbreeding
Inbreeding involves the repeated fusion of gametes from generations of close relatives
What is inbreeding depression
Inbreeding depression can arise due to the accumulation of homozygotes recessive allele is for harmful jeans
What type of plants are not susceptible inbreeding depression and why
Self pollinating plants don’t suffer from this as harmful alleles have been lost through natural selection
What is an F1 hybrid
F1 hybrid is introduced by crossing a cultivar or a breed with an individual with a different genotype
Why are F1 hybrid is not bread together to produce F2 offspring
If the F1 generation were cross together the F2 generation would show too much variety
What does inbreeding depression do
Inbreeding depression makes the plants small have less vigour yield and fertility
What does crossbreeding do
Crossbreeding create hybrid plants which increase in size vigger and yield this is called hybrid vigosity
Three reasons why plant field trials are carried out
To compare the performance of plant cultivars under the same environmental conditions
To test the performance of one plan under different environmental conditions
To evaluate the overall performance of a GM crop
Distinguish between the terms inbreeding and crossbreeding in terms of heterozygosity and homozygosity
Inbreeding decreases heterozygosity and increases homozygosity
Crossbreeding decreases homozygosity and increases heterozygosity
Why is genome sequencing useful to breeders
Gino sequencing can be used to identify a desired characteristics in plants
Give an example of an improvement has been made to a crop by modifying them genetically
By adding the BT toxin which gave them pest resistance
Glyphosphate which is resistant to herbicide
