| A | B |
|---|
| genetics | the study of heredity (how parents pass their traits to their offspring). |
| DNA | genetic material found in the nucleus that determines the traits of an organism |
| trait | a special thing (characteristic) of an organism. Traits are |
| gene | basic unit of heredity. They are found on the cell’s chromosomes. Genes determine all the traits of an organism |
| allele | each member of a gene pair. Alleles are written using two letter (RR, rr, or Rr). |
| Punnett Square | chart made by Reginald Punnett, an English geneticist. It is used to show possible combinations of the cross between two organisms |
| dominant | gene with the stronger trait. The dominant gene is usually the one we can see (ex: straight hair or curly hair), written with an upper case letter. |
| recessive | weak gene with the hidden trait. You usually cannot see the recessive gene, but it does exist on the chromosome, using a lower case letter |
| phenotype | traits, or characteristics, of an organism that we can see |
| genotype | genetic makeup of an organism |
| probability | possibility, or chance, that something may or may not happen |
| chromosome | rod-shaped cell structures, made of DNA, that hold all the genetic information of the cell. It controls all the activities of a cell and passes on the traits of a cell to new cells |
| incomplete dominance | when a gene is neither dominant nor recessive. So, the genes blend together. |
| mitosis | duplication and division of the nucleus and of the chromosomes during cell reproduction. The parent cell copies its DNA and then splits into two daughter cells. Daughter cells =parent cell |
| meiosis | process that results in cells with only half the normal number of chromosomes. Human sex cells undergo meiosis so that they only have 23 chromosomes each |
| hybrid or heterozygous | (Rr, rR), genes are different, one allele is weak and one is strong. |
| Purebred or homozygous | Genes have the same allele; both dominant or both recessive. (RR, rr) |
| heredity | process whereby you receive the genes from your parents that determine your traits. |
