| A | B |
|---|
| phenotype | what the trait looks like |
| genotype | the genetic code for a trait |
| trait | factors or characteristics of an organism |
| heredity | the passing of traits from parents to their offspring |
| genetics | the study of heredity |
| dominant | the trait that will be expressed in a hybrid |
| recessive | the trait that will be hidden 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 | a form of a gene |
| chromosome | found in the nucleus of every cells, contains instructions for everything the cell does |
| 46 | the number of chromosomes humans have in body cells (diploid cells) |
| sex chromosomes | the 23rd pair of chromosomes that in addition to genes, also determine sex |
| XY | letters that stand the male chromosomes |
| XX | letters that stand for the female chromosomes |
| replicates | make an exact copy of itself - chromosomes do this |
| meiosis | the type of cell division that results in eggs and sperm |
| mitosis | the kind of cell division which all cells do to grow and repair |
| gametes | sperm or egg: contains 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 in heterozygous individuals, 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 |
| polygenic | trait like height or skin color that is determine by more than 1 pair of genes |
| multiple alleles | trait controlled by one gene, but the gene comes in more that 2 forms of an allele |
| complete dominance | One trait is completely dominant over another; when heterozygous, the dominant allele is expressed |
