| Question |
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| Answer |
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| 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 |
| purebred |
an organism that always produces offspring with the same form of a trait as the parent (homozygous) |
| gene |
a segment of DNA on a chromosome that codes for a specific trait |
| alleles |
the different forms of a gene |
| dominant allele |
an allele whose trait always shows up in the organism when the allele is present; masks the recessive allele |
| recessive allele |
an allele that is masked when a dominant allele is present |
| hybrid |
an organism that has two 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 organism’s genetic makeup, or allele combinations |
| homozygous |
having two identical alleles for a trait |
| heterozygous |
having two different alleles for a trait |
| codominance |
a condition in which neither of two alleles for a trait is dominant nor recessive ; both alleles are expressed in the offspring |
| sperm |
a male sex cell |
| egg |
a female sex cell |
| meiosis |
the process that occurs in sex cells (sperm and egg) by which the number of chromosomes is reduced by half |
| mutation |
a change in a gene or chromosome |
| mitosis |
the stage of the cell cycle during which the cell’s nucleus divides into two new nuclei and one copy of the DNA is distributed into each daughter cell |
mr. charles11
