| A | B |
|---|
| genetics | scientific study of heredity |
| fertilization | process in sexual reproduction in which male and female reproductive cells join to form a new cell |
| trait | specific characteristic of an individual |
| hybrid | offspring of crossess between parents with different traits |
| gene | sequence of DNA that codes for a protein and thus determines a trait; factor that is passed from parent to offspring |
| allele | one of a number of different forms of a gene |
| principle of dominance | Mendel's second conclusion, which states that some alleles are dominant and others are recessive |
| segregation | separation of alleles during gamete formation |
| gamete | sex cell |
| probability | likelihood that a particular event wil occur |
| homozygous | having two indentical alleles for a particular gene |
| heterozygous | having two different alleles for a particular gene |
| phenotype | physical characteristics of an organism |
| genotype | genetic makeup of an organism |
| Punnett square | diagram that can be used to predict the genotype and phenotype combination of a genetic cross |
| independent assortment | one of Mendel's principles that states the gense for different traits can segregate independently during the formation of gametes |
| incomplete dominance | situation in which one allele is not completely dominant over another allele |
| codominance | situation in which the phenotypes produced by both alleles are completely expressed |
| multiple alleles | a gene that has more than two alleles |
| polygenic trait | trait controlled by two or more genes |
| homologous | term used to refer to chromosomes in which one set comes from the ale parent and one set comes from the female parent |
| diploid | term used to refer to a cell that contains two sets of homologous chromosomes |
| haploid | term used to refer to a cell that contains only a single set of genes |
| meiosis | process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell |
| tetrad | structure cintaining four chromatids that forms during meiosis |
| crossing-over | process in which homologous chromosomes exchange portions of their chromatids during meiosis |
| zygote | fertilized egg |
