Sustainability and Interdependence - Plant and Animal Breeding Flashcards
cultivar
a variety of plant obtained by natural selection and/or genetic manipulation and maintained by cultivation
hybrid vigour
improved characteristics shown by offspring from crossing inbred parental strains with different desirable traits
crossbreeding
individuals from different breeds reproduce to try and produce offspring superior to both parents
inbreeding
the fusion of two gametes from close relatives over many generations to produce an organism which is true-breeding for the desirable characteristic(s)
inbreeding depression
- forcing natural outbreeders to inbreed increases the frequency of individuals homozygous for recessive deleterious alleles
- this results in individuals struggling to survive and reproduce
outbreeding
the fusion of two gametes from unrelated members of the same species
selective breeding
only organisms with the best characteristics are chosen to breed for the next generation
designing a plant field trial
reliable and valid trails require…
- selections of treatments to be used
- number of replicates to be included
- randomisation of treatments
selection of treatments
field trials
- each equal sized plot must be given the treatment e.g. high/low concentration of fertiliser
- all other variables must be kept constant to allow for a fair comparison
number of replicates
field trial
- uncontrolled variability exists within each sample as no two samples are identical - experimental error
- several replicates take into account the variability, reducing the effect of experimental error
randomisation of treatments
field trial
treatments should be random to eliminate the possibility of bias
why is the f2 generation not useful?
produced by f1 hybrid
since the f1 are not true-breeding, if they breed to produce f2 generation, the offspring wuold show too much variation meaning they would lack many of the desirable characteristics
