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=Genetics Wiki= By: Andrew Hanson & Matt Goulet =What is genetics?= Genetics is the study of heredity. Like how you have the certain traits that make who you are. We will get into more detail as you read on.

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=Punnett Square= Take the two sets of genes that you are working with and place the Upper case in front of the lower case if the situation calls for it. Simply find where the two meet and combine their letters This square for instance would be RR, Rr, Rr, and rr. This gene is dominant and I will explain why in a bit.

Dominant and Recessive Genes
When you see a chromosome represented by a upper case letter, it is dominant. When the chromosome represented by a lower case letter, it is recessive. If a dominant gene is paired with =Alleles= The alternative form of a gene. =Cross-Fertilization= The fusion of male and female sex cells from different individuals of the same species. For example if you cross a purple and white flower, the sperm from the pollen of one flower fertilizes the eggs in the flower of a different plant. The fertilized eggs then develop into embryos within seeds. =Hybrid= The offspring of two different true-breeding varieties. The process of hybridization is important biologically because it increases the genetic variety within a species, which is necessary for evolution to occur. =Monohybrid Cross= A pairing in which the parent plants differ in only one character. =Homozygous= Refers to having identical alleles for a single trait. An example would be, the gene for seed shape in pea plants exists in two forms, one form for round seed shape (R) and the other for wrinkled seed shape (r). A homozygous plant would contain the following alleles for seed shape (RR) or (rr). =Heterozygous= Having two different alleles for a single trait. An example for that is the gene for seed shape in pea plants exists in two forms, one form for round seed shape (R) and the other for wrinkled seed shape (r). A heterozygous plant would contain the following alleles for seed shape (Rr). =Phenotype and Genotype= Phenotype is a trait that is observable, like hair color. A genotype is the genetics makeup, the particular set of genes it possesses. =Testcross= Breeds an individual of unknown genotype, but dominant phenotype. =Dihybrid Cross= Crossing organisms differing in two characters. =Codominance= A heterozygote (a person possessing two different forms of a particular gene that expresses both traits) expresses both traits. This differs from intermediate inheritance, the individuals phenotype is not intermediate, but shows the separate traits of both alleles. =Chromosome Theory of Inheritance= States that genes are located on chromosomes, and the behavior of chromosomes during meiosis and fertilization accounts for inheritance patterns. =Gene Locus= Where the alleles of a gene reside. =Genetic Linkage= The tendency for the alleles on one chromosome to be inherited together. The closer two genes are, the greater the genetic linkage. =Sex-Linked Gene= Any gene that is located on a sex chromosome.

This is a video about genetics made by a teacher. []