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genetics part 1
genetic terms
| Term | Definition |
|---|---|
| Traits | physical characteristics like eye or hair color |
| Heredity | The passing of traits from parents to offspring |
| Genetics | Scientific study of Heredity |
| Gene | factors that control traits (a portion of DNA) |
| Allele | Different forms of a gene (ex. one for short and for tall) |
| Dominate allele | one who's trait always shows up in an organism when the allele is present |
| Recessive allele | One whose trait is masked or covered up when the dominate allele is present |
| Gregor Mendel | Father of genetics |
| DNA | -deoxyribonucleic acid- -a chemical molecule that carries all of the cell’s instructions. Code for life. |
| Double helix | Shape of DNA -looks like a twisted ladder |
| homozygous or purebred | organism that has the same 2 alleles for a trait; always produces offspring with the same form of a trait as the parents (purebred) (GG or gg) |
| heterozygous or hybrid | An organism that has 2 different alleles for trait ; hybrid(Gg) |
| dominant trait symbol | A capital letter |
| recessive trait sysmbol | A lower case letter |
| number chromosomes in human body cells | 46 |
| number of PAIRS of chromosomes in human body cells | 23 |
| number of chromosomes in human sex cells | 23 |
| sex cell chromosome number | always 1/2 the number of chromosomes in the body cells |
| probability | Chance that trait will show up in the offspring |
| Punnett Square | Chart that shows all the possible combinations of alleles that can result from a genetic cross |
| Phenotype | physical appearance or visible trait that you can see expressed in the offspring ( tall or short) |
| Genotype | organism's genetic makeup or allele combination, this you can't see( TT ot Tt or tt) |