| A | B |
|---|
| trait | a characteristic that an organism can pass on to its offspring through its genes |
| heredity | the passing of traits from parents to offspring |
| genetics | the scientific study of heredity |
| purebread | an organism that always produces offspring with the same form of a trait as the parent |
| gene | a segment of DNA on a chromosome that codes for a specific trait |
| allele | a different form of gene |
| dominant allele | an allele whose trait always shows up in the organism when the allele is present |
| recessive allele | an allele that is masked when a dominant allele is present |
| hybrid | an organism that has different alleles for a trait: an organism that is heterozygous for a particular trait |
| probability | the likelihood that a particular event will occur |
| Punnett square | a chart that shows all the possible combinations of alleles that can result from a genetic cross |
| phenotype | an organism's physical appearance or visible traits |
| genotype | an organsim's genetic makeup, or allele combination |
| homozygous | having 2 identical alleles for a trait |
| heterozygous | having 2 different alleles for a trait |
| codominance | a condition in which neither of two alleles of a gene is dominant or recessive |
| sperm | a male sex cell |
| egg | a female sex cell |
| meiosis | the process that occurs in sex cells(sperm & egg) by which the number of chromosomes is reduced by half |
| messenger RNA | RNA that copies the coded message from DNA in the nucleus ans carries the message into the cytoplasm |
| transfer RNA | RNA in the cytoplasm that carries an amino acid to the ribosome and adds it to the growing protein chain |
| mutation | a change in a gene or chromosome |
