Inherited Change Flashcards
What affects the phenotype
Environment and genotype
What is monohybrid inheritance
Inheritance of one gene
What are the rules of genetic diagrams
Choose letter of dominant characteristic and make a capital (as long as the diff between capital and lower case is obvious)
State parent pheno and genotype
State gametes
Use punnets square
State genotypic and phenotypic ratio
Define dihybrid inheritance
Inheritance of two genes on different chromosomes
What is mendels law
Law of independent assortment
Any allele may combine randomly with any other allele of a different gene
Define co-dominance
When both alleles are dominant and so are expressed in the phenotype
How do you depict codominance in a punnet square
Use superscript of a letter which represents the gene
Define multiple alleles
Gene has 2 or more alleles
Define sex linkage
When a gene is found on the X chromosome but no on the y
Why are reccesive characteristics more frequent in men
No equivalent homologous portion on y so only one recessive alelle needed as oppose to two
Why do men always inherit sex linked disease from their mother
Their dad gives y and mum gives X along with alleles that are sex linked
Define autosomal linkage
Two genes are on the same chromosome
What is different about the gametes produced in autosomal linkage
Two alleles are linked so only two possible gametes likely
Ab aB
No longer in equal proportion
Define epistasis
When one gene affects the expression of another
Give examples of epistasis
Coat colour
Gene for melanin production
Another for distribution
Biochemical pathways
Genes for each enzyme
