Plant and Animal Breeding 3.2 Flashcards
What characteristics are needed for sustainable food sources
Higher yield; Higher nutritional values; Resistance to disease and pests; Ability to grow in particular environments
What are plant field trials
Enables the comparison of performances of different cultivars or treatments and to evaluate GM crops. Often carried out in a range of environments
How do you get a successful field trial
Randomisation of treatments; number of replicates; selection of treatments; repeats in other environments
Why is randomisation of treatments good
To prevent bias existing in the system
Selection of treatments
With one variable factor, a fair comparison could be made
Why is the number of replicates important
To take experimental error (uncontrolled variability) into account
Why should field trials be repeated in other environments
Without it the conclusion may be limited, they find out which soil type and climate conditions suit the plant best
What is inbreeding
When closely related organisms breed
What are issues of inbreeding
Increased frequency of individuals homozygous for recessive deleterious alleles; consequent reduction in survival to reproduction ages; inbreeding depression is the resultant effect
What is inbreeding depression
The accumulation of recessive, deleterious and homozygous alleles
What is cross breeding
Different breeds of animals crossed to produce improved characteristics in the cross-bred population
What are F1 Hybrids
Different imbred lines of plants can be crossed to produce a relatively uniform heterozygous crop. They show increased vigour (disease resistance and growth rate) and yield.
Why are F1 Hybrids not usually bred together
The F2 produced shows too much variation
