mendelian genetics part two

3 laws of inheritance

law of dominance, law of segregation, law of independent assortment

law of dominance

in a heterozygote, 1 dominant trait will conceal the presence of another trait for the same character

law of segregation

paired genes must separate equally into gametes such that offspring have an equal likelihood of inheriting either

multiplication rule

(segregation) the probability that 2 or more independent events will occur at the same time is the product of their individual proababilities

law of independent assortment

gene don’t influence each other when sorting of alleles for every gene is equally likely to occur

dihybrid cross

crossing two true-breeding parents that differ in two characters

how would you find ratios using a trihybrid cross?

multiply

3 violations to law of independent assortment

linkage, gene interaction, epistasis

linkage

genes that are located physically close to each other on the same chromosome are more likely to be inherited as a pair

gene interaction

single trait is controlled by two or more genes, each of which has 2 or more alleles

epistasis

alleles of one gene mask expression of alleles of another gene

in most organisms, the sex of the individual is determined by

sex chromosomes

x-linked

a gene that occurs on the X chromosome but not the Y

biologically female

XX

biologically male

XY