| A | B |
|---|
| phenotype | what the trait looks like |
| heredity | the passing of traits from parents to their offspring |
| dominant | the trait that will be expressed in a hybrid |
| hybrid | an organism with different genes for the same trait, one from each parent |
| homozygous | has the same genes or alleles for a trait |
| heterozygous | having different genes or alleles for a trait |
| Gregor Mendel | austrian monk - father of modern genetics |
| genes | a section of DNA which controls a trait |
| alleles | another name for a gene |
| DNA | deoxyribose nucleic acid |
| one strand of DNA | what makes up a chromosome |
| chromosome | found in the nucleus of every cells, contains instructions for everything the cell does |
| 23 pairs | the number of chromosomes humans have |
| the 23rd pair | called the sex chromosomes because determine whether you are male or female |
| XY | letters that stand the male chromosomes |
| XX | letters that stand for the female chromosomes |
| replication | a copy is made of the DNA |
| meiosis | the type of cell division that results in eggs and sperm |
| the egg | contains half the number of chromosomes |
| sperm | contain one half the number of chromosomes |
| fertilized egg | contains the full number of chromosomes |
| Punnett Square | the chart used to determine possible genotypes of offspring |
| codominance | 2 forms of the same gene are expressed at the same time WITHOUT BLENDING, ex.some cattle have white hair and red hair |
| incomplete dominance | blending of traits instead of dominance, ex. in flowers a red gene and a white gene result in a pink flower |
| sex-linked traits | traits that are caused by genes on the X chromosome, but not on the Y |
| sex chromosome | the 23rd pair of chromosome in humans |
| sickle-cell anemia | inherited disease which causes red blood cells to take on a sickle shape |
| multiple alleles | a single trait is caused by the action of 2 of several genes, ex. human eye color could be green, blue, brown, hazel, gray |
