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Chapter 13-Genetics
| Term | Definition |
|---|---|
| heredity | the passing of traits from parent to offspring |
| genetics | the study of how traits are passed from parent to offspring |
| Mendel | considered the father of genetics |
| dominant trait | a genetic factor that blocks another factor |
| recessive trait | a genetic factor that is blocked by the presence of a dominant factor |
| gene | a section on a chromosome that has genetic information for one trait |
| alleles | the different forms of a gene |
| phenotype | how a trait appears or is expressed |
| genotype | the two alleles that control the phenotype of a trait |
| homozygous | when the two alleles of a gene are the same |
| heterozygous | when the two alleles of a gene are different |
| Punnett Square | a model used to predict possible phenotypes and genotypes of offspring |
| pedigree | a chart that shows phenotypes of genetically related family members |
| incomplete dominance | when an offspring's phenotype is a combination of the parents' phenotype (like pink flowers from red and white) |
| codominance | when both alleles can be observed in a phenotype (like roan coat color in cattle, a blend of red and white hairs, inherited from each parent) |
| multiple alleles | genes that have more than two alleles to be selected from , like blood type |
| polygenic inheritance | when multiple genes determine the phenotype of a trait, like hair and eye color |
| DNA | an organism's genetic material |
| nucleotide | a molecule made of a nitrogen base, a sugar, and a phosphate group |
| adenine, guanine, cytosine, thymine | the 4 nitrogen bases that make up DNA |
| replication | the process of copying a DNA molecule to make another DNA molecule |
| junk DNA | segments of DNA that do not form genes |
| RNA | a type of nucleic acid that helps to make proteins (3 kinds) |
| mutation | a change in the sequence of a gene |