Genes Made up of DNA Located on the Chromosomes During Meiosis pairs of genes separate and each new cell gets one form of a gene for a specific trait. Genes may have different forms and we call these Alleles. Always come in pairs (two genes for each trait.) An organism recieves two genes for each trait, one from each parent. One of these genes may be stronger or more Dominant , so it overpowers the other and shows up in the offspring. The gene not expressed is called the recessive gene. Two forms of a gene(alleles) that are the same produce a homozygous organism. Two forms of a gene (alleles) that are different produce a heterozygous organism. Organisms that receive 2 of the same gene type – both dominant or both recessive will have pure traits Ex. A cow has two genes for black color, which is dominant in some breeds. Any offspring of that animal will be black. This animal is considered homozygous with a pure dominant trait for color. A cow that has genes for a red color is also considered pure, however because red is a recessive trait they would be considered homozygous pure with a pure recessive trait for color. Organisms with two unlike genes for a certain trait are called Hybrid. A cow with a dominant gene for black color and recessive gene for red color is considered a hybrid for that trait. The offspring from a pure black bull bred to a pure red cow would be what? An organism may be Dominant in certain traits and recessive in others. Dominant traits in one organism may be recessive traits in another organism.