| A | B |
|---|
| chromosome | Bundles of long strands of DNA |
| gene | A heritable factor that controls a specific characteristic |
| allele | Variation of a gene |
| mutation | Random, rare change in genetic material |
| base substitution mutation | Mutation in which one base is changed |
| homologous chromosomes | Chromosomes that are similar in shape and size and carry the same genes |
| meiosis | Form of cell division called a reduction division that results in the formation of gamets |
| karyotype | Photograph of chromosomes arranged according to a standard format |
| genotype | Symbolic representation of a pair of alleles possessed by an organism; represented by 2 letters |
| phenotype | Characteristics or traits of an organism |
| dominant allele | Allele that has the same effect on the phenotype whether it is paired with the same allele or a different one |
| recessive allele | An allele that has an effect on phenotype only when present in a homozygous state |
| locus | Particular position on homologous chromosomes of a gene |
| homozygous | Having 2 identical alleles of a gene |
| heterozygous | Having 2 different alleles of a gene |
| carrier | Individual who has a recessive allele of a gene that does not have an effect on their phenotype |
| test cross | Testing a suspected heterozygote by crossing it with a known homozygous recessive |
| sex-linkage | Genetic trait whose locus is on the X or Y chromosome |
| pedigree chart | Record of an organism's ancestry |
| polymerase chain reaction | Laboratory technique which takes a very small quantity of DNA and copies all nucleic acids in it to make millions of copies of the DNA |
| gel electrophoresis | Laboratory technique used to separate fragments of DNA in an effort to identify its origin |
| genome | A catalogue of all of the bases an organisms possesses |
| gene transfer | Technique of taking a gene out of one organism and placing it in another organism |
| clone | A group of genetically identical organisms or a group of cells artificially derived from a single parent |
| therapeutic cloning | The production of embryonic stem cells for use in replacing or repairing damaged tissues or organs |
| independent assortment | When gametes are formed, the separation of one pair of alleles between the daughter cells is independent of the separation of another pair of alleles |
| dihybrid cross | Cross involving 2 traits with 2 alleles each |
| polygenic inheritance | Two or more genes influence the expression of one trait |
| codominant alleles | Pairs of alleles that both affect the phenotype when present as a heterozygote |
| haploid | Possessing one set of chromosomes (half of the parent cell) |
| diploid | Possessing 2 sets of each chromosome |
| autosomes | Any chromosome which is not a sex chromosome |
| crossing over | Exchange of genetic material between non-sister chromatids |
| linkage group | Any 2 genes found on the same chromosome |
| true-breeding | Homozygous |
