| A | B |
|---|
| phenotype | what the trait looks like |
| genotype | the genetic code for a trait; the alleles inherited |
| trait | factors or characteristics of an organism |
| heredity | the passing of traits from parents to their offspring |
| genetics | the study of heredity |
| examples of inherited traits | examples: eye color, hair color, tall or short, tongue roll, cleft chin |
| 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 |
| purebred | an organism which has the same genes for a 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 |
| pea plants | the kind of plant Mendel used in his study of heredity |
| genes | a section of DNA which controls a trait |
| alleles | another name for a gene |
| DNA | deoxyribose nucleic acid; what chromosomes are made out of. |
| 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 |
| 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 |
| both parents | all body cells contain genetic instructions from ------ ------- |
| the egg | female gamete that contains half the number of chromosomes |
| sperm | male gamete that 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 |
| mutation | a change in the gene pattern |
| sex chromosome | the 23rd pair of chromosome in humans |
| carrier | the individual which carries the recessive gene for a trait |
| 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 |
| test cross | a cross done with a homozygous recessive organism with an organism of an unknown genotype to determine what the unknown genotype is. |
| acquired trait | a trait acquired during an organism's lifetime, not inherited. |
| pedigree | a chart that shows the inheritance patter of the trait through a family |
