Sources of genetic variations
Mutation
Sexual Reproduction (Meiosis)
Mutation Defintion
A permanent change to the base sequence of DNA that creates NEW ALLELES
What two types of mutations are there?
Which are inherited ?
Gametic can be inherited
Somatic cannot be inherited unless in asexual reproduction
Genetic Variation/diversity definition?
The variation in genetic make-up/total number of genetic characteristics in a species/population.
Meiosis definition
A cell division that produces 4 genetically unique daughter cells. Each daughter cell has half the number of chromosomes from the parent cell (n=23, 2n=46). Meiosis produces sex cells (gametes) for sexual reproduction.
Crossing over process when and where?
A random exchange of chromosome segments (chromatids) between homologous pair chromosomes.
Happens in prophase 1 of meiosis 1 and result in a NEW COMBINATION OF GENES
Crossing over and recombination
Recombination is an exchange of genetic material between adjacent chromatids (non-sisters chromatids) of homologous chromosomes. This results in unique combinations of alleles on chromosomes, creating almost infinite potential for variation.