| A | B |
|---|
| traits | Inherited features of an organism. |
| heredity | The passing of traits from parents to young. |
| genetics | The scientific study of heredity. |
| Gregor Mendel | The father of genetics. |
| cross-pollination | The process of transferring pollen from one plant to another. |
| purebred | An organism that results from a cross of parents who have the same form of a trait. |
| hybrid | An organism that results from a cross of parents that have different forms of a trait. |
| dominant trait | A trait that prevents the showing of another trait. |
| recessive trait | A trait that is hidden in the presence of a dominant trait. |
| Organisms inherit traits in _____. | pairs |
| A recessive trait is shown only when no _____ trait is present. | dominant |
| tallness | Dominant trait over shortness for stem length of pea plants. |
| T | Symbol for tallness. |
| t | Symbol for shortness. |
| TT | Purebred tall pea plant. |
| Tt | Hybrid tall pea plant. |
| tt | Short pea plant (has to be purebred). |
| phenotype | The appearance of an organism (the plant is TALL and GREEN) |
| genotype | The genetic makeup of an organism (TT, Tt, tt) |
| Punnett square | A table that shows all the possible combinations of traits among offspring produced in a cross. |
| chromosomes | Threadlike cell structures that contain DNA and control heredity. |
| genes | A section of a chromosome that carries the information for a single trait. |
| sex chromosomes (X & Y) | Chromosomes that determine the sex of a human. |
| X chromosome | Sex chromosome that is found in both males and females. |
| Y chromosome | Sex chromosome found only in males. |
| sex-linked trait | A trait that results from a gene found on the X chromosome but not on the Y. |
| selective breeding | The crossing of organisms with useful traits to make offspring that will also have those useful traits (big tomatoes). |
| genetic engineering | The technology of transferring genes from one organism to another. |
