3.2 plant + animal breeding Flashcards
Desirable breeding traits
High nutritional values
Pest and disease resistance
High crop yield
Survive environmental conditions
Randomised field trials
An investigation set up to determine which plant performs the best in a certain environment, using randomisation of treatments .
Non random field trials
An investigation set up to determine which crop performs the best in a certain environment, without using randomisation of treatments
Factors of considerations for random field trials
Selection of treatments
Number of replicates
Randomisation of treatments
Factors of consideration for non random field trials
Selection treatments and number of replicates.
Selection of treatments
Where there is only one variable altered in an investigation, by controlling and keeping all other variables constant.
Number of replicates
Repeating an experiment at least 3 times to ensure increased reliability. Taking an average
Randomisation of treatments
Preventing any biased in an investigation, by randomly selecting the area in which crops are allocated to grow.
What can field trials test
What type of crop is suitable in a field
Whether GM crops are more effective than naturally occurring crops.
Inbreeding definition
The fusion of two gametes from close relatives, for the purpose of eliminating heterozygotes from a gene pool over many generations.
Heterozygotes definition
Organisms which contain both a dominant and recessive allele as part of their genotype.
Homozygous definition
Organisms which have a pair of dominant alleles or recessive alleles as part of their genotype.
Disadvantages of inbreeding
Inbreeding depression can occur - which is where there is an increase in recessive homozygosity.
Why is inbreeding depression bad
Because the recessive homozygosity could mean that organisms develop deleterious Alleles, which are alleles that would cause harm in an organism.
Allele definition
A specific form of a gene
Phenotype definition
The physical traits that an organism expresses. (Written in words).
Genotype definition
The genes that an organism has. (Written in letter Bb)
Cross breeding definition
Where two completely different breeds of animal mate to produce offspring, called a crossbreed.
Purpose of cross breeding
To produce potential improved characteristics.
(Also to make dogs look different)
Methods of introducing new alleles
Cross breeding and mutation.
Hybrids definition
Where there has been a crossing of two different inbred plant lines.
F1 hybrid definition
Where there has been the crossing of two different inbred parents.
Advantages of F1 hybrids
F1 hybrids typically are heterozygous crops, which have increased vigour and yield, they typically also are disease resistant and increased rate of growth.
F2 hybrid definition
Where two F1 hybrids are bred together.
