| Term | Definition |
|---|
| gene | section of DNA that codes for a protein and determines a trait |
| trait | specific characteristic that varies from one individual to another |
| allele | form of a gene |
| dominant | trait that will show up in an organism's phenotype if gene is present |
| recessive | trait that will only appear in the phenotype if organism inherits two of them; covered up by the dominant gene |
| segregation | separation of alleles during meiosis or gamete formation |
| gamete | sex cell; sperm or egg |
| hybrid | offspring of a cross between parents with different traits; heterozygous |
| true-breeding | inherited two identical alleles for a trait; homozygous or purebred |
| probability | likelihood an event will occur |
| phenotype | physical characteristics of an organism |
| Punnett square | diagram that shows the possible results of a genetic cross; parents' gametes on top and left, offsprings' genotypes inside |
| genotype | genetic makeup of an organism |
| homozygous | has two identical alleles for a particular trait; true-breeding or purebred, ex. PP or pp |
| heterozygous | has two different alleles for a particular trait; hybrid, ex. Pp |
| independent assortment | principle that genes do not influence each other's inheritance because they are separated independently during meiosis |
| multiple alleles | three or more alleles exist for a particular trait |
| incomplete dominance | creates a blended phenotype; one allele is not completely dominant over the other |
| polygenic trait | trait controlled by two or more genes; shows a wide variety of phenotypes |
| codominance | both genes contribute to the phenotype of the organism, ex. spotted or striped |
| nondisjunction | error in meiosis in which homologous chromosomes don't separate; gametes end up with wrong number of chromosomes |
| sex-linked trait | trait related to a gene that is found on the X or Y chromosomes |
Combine with other sets
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