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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) |