Simple Mendel Genetics

blue = sire pink = doe purple = litter outcome Color key: blue = sire  pink = doe purple = litter outcome  Definitions: alleles - it takes two alleles to form a certain trait. Offspring receive one allele per trait from each parent. dominant trait - A trait that will show on the offspring if one of the parents passes it on. Dominant genes are represented by upper case letters (ex. agouti [A/A] is dominant to black [a/a]. All of the offspring from this pairing will be agouti carrying black, in other words, heterozygous agouti [A/a]) heterozygous - Having two different alleles for a single trait (ex. A/a - agouti carrying black) homozygous - Having identicle alleles for a single trait. (ex. A/A and a/a) recessive trait - A trait that must be passed on to the offspring by both parents in order to express itself. Recessive genes are represented by lower case letters. (ex. dwarfism is a recessive gene [dw/dw] the only way to get dwarf offspring is by breeding a dwarf to another dwarf [resulting in 100% dwarf offspring], dwarf to dwarf carrier [resulting in 50% dwarf offspring], or dwarf carrier to dwarf carrier [resulting in 25% dwarf offspring]) The following calculations are assuming that neither parent carries recessives other than the ones listed in their charts. homozygous agouti x homozygous agouti    A A  A  A/A  A/A  A  A/A  A/A 100% homozygous agouti offspring [A/A] heterozygous agouti x homozygous agouti    A A  A  A/A  A/A  a  A/a  A/a    50% homozygous agouti offspring [A/A]    50% heterozygous agouti offspring [A/a]   heterozygous agouti x heterozygous agouti    A  a  A  A/A  A/a  a  A/a  a/a 25% homozygous agouti offspring [A/A] 50% heterozygous agouti offspring A/a] 25% black offspring [a/a]  homozygous agouti x black    a  a  A  A/a  A/a  A  A/a  A/a 100% heterozygous agouti offspring [A/a]   heterozygous agouti x black  a  a  A  A/a  A/a  a  a/a  a/a 50% heterozygous agouti offspring [A/a] 50% black [a/a]  black x black    a  a  a  a/a  a/a  a  a/a  a/a 100% black offspring [a/a]   homozygous black x blue    g  g  G  G/g  G/g  G  G/g  G/g 100% heterozygous black offspring [a/a G/g] *blue is recessive to black, therefore black is represented by G-  heterozygous black x heterozygous black    G  g  G  G/G  G/g  g  G/g  g/g 25% homozygous black offspring [a/a] 50% heterozygous black [a/a G/g] 25% blue [a/a g/g] *blue is recessive to black, therefore black is represented by G- blue x blue     g  g  g  g/g  g/g  g  g/g  g/g 100% blue offspring [a/a g/g] dwarf x standard size (does not carry dwarfism)    Dw  Dw  dw  Dwdw  Dwdw  dw  Dwdw  Dwdw 100% standard size carrying dwarfism [Dwdw] dwarf carrier x dwarf carrier    Dw  dw  Dw  DwDw  Dwdw  dw  Dwdw  dwdw 25% standard size not carrying dwarfism [DwDw] 50% standard size carrying dwarfism [Dwdw] 25% dwarves [dwdw] dwarf x dwarf    dw  dw  dw  dwdw  dwdw  dw  dwdw  dwdw 100% dwarves [dwdw] dwarf x standard size (dwarf carrier)    Dw  dw  dw  Dwdw  dwdw  dw  Dwdw  dwdw 50% standard size carrying dwarfism [Dwdw] 50% dwarves [dwdw] dumbo x standard ear (does not carry dumbo)    Du  Du  du  Dudu  Dudu  du  Dudu  Dudu 100% standard eared carrying dumbo [Dudu] dumbo carrier x dumbo carrier    Du  du  Du  DuDu  Dudu  du  Dudu  dudu 25% standard eared - do not carry dumbo [DuDu] 50% standard eared carrying dumbo [Dudu] 25% dumbos [dudu] dumbo x dumbo    du  du  du  dudu  dudu   du  dudu  dudu 100% dumbos [dudu] dumbo x standard eared (dumbo carrier)    Du  du  du  Dudu  dudu  du  Dudu  dudu 50% standard eared carrying dumbo [Dudu] 50% dumbos [dudu] hairless x standard hair (does not carry hairless)    Hr  Hr  hr  Hrhr  Hrhr  hr  Hrhr  Hrhr 100% standard hair carrying hairless hairless carrier x hairless carrier    Hr  hr   Hr  HrHr  Hrhr  hr  Hrhr  hrhr 25% standard hair - do not carry hairless [HrHr] 50% standard hair carrying hairless [Hrhr] 25% hairless [hrhr] hairless x hairless    hr  hr  hr  hrhr  hrhr  hr  hrhr  hrhr 100% hairless [hrhr] hairless x standard hair carrying hairless    Hr  hr  hr  Hrhr  hrhr  hr  Hrhr  hrhr 50% standard hair - carrying hairless [Hrhr] 50% hairless [hrhr] standard hair x rex hair    Re  re  re  Rere  rere  re  Rere  rere 50% Rex - carrying standard hair [Rere] rex x rex    Re  re  Re  ReRe  Rere  re  Rere  rere 25% double rex [ReRe] 50% rex - carrying standard hair [Rere] 25% standard hair [rere] Standard hair x double rex    Re  Re  re  Rere  Rere  re  Rere  Rere 100% rex [Rere] rex x double rex    Re  Re  Re  ReRe  ReRe  re  Rere  Rere 50% double rex [ReRe] 50% rex [Rere] double rex x double rex    Re  Re  Re  ReRe  ReRe  Re  ReRe  ReRe 100% double rex [ReRe] ta