| A | B |
|---|
| Allele | Variations of genes that determine traits in organisms; the two corresponding alleles on paired |
| Chromosome | A structure made of coiled DNA that transfers hereditary information to the next generation. |
| Codon | A sequence of three nucleotides which together form a unit of genetic code in a DNA molecule. |
| Cross | The transfer of sperm from one plant to the egg of another plant of the same species. |
| Deoxyribonucleic Acid (DNA) | A molecule that contains an organism’s genetic information. |
| Dominant | A form of gene that is expressed as the trait when a dominant allele is present. |
| Feature | A structure, characteristic, or behavior of an organism, such as eye color, plant height, or timing of migration. |
| Gene | The basic unit of heredity carried by the chromosomes; codes for proteins which determine the traits of an organism. |
| Generation | Offspring that are at the same stage of descent from a common ancestor. |
| Genetics | The study of genes and how they affect the traits of an organism. |
| Genotype | An organism’s particular genetic makeup. |
| Heredity | The passing of traits from parent to offspring. |
| Heterozygous | A gene composed of two different alleles (a dominant and a recessive). |
| Homozygous | A gene composed of two identical alleles. |
| Inheritance | The passing on of genetic traits from parents to offspring. |
| Nitrogenous bases | An organic molecule with a nitrogen atom that has the chemical properties of a base. DNA is made of four nitrogenous bases: adenine, thymine, cytosine, and guanine. |
| Nucleotide | Organic molecules composed of three subunit molecules: a nitrogenous base (also known as nucleobase), a five-carbon sugar (ribose or deoxyribose), and a phosphate group; make up DNA. |
| Phenotype | The traits produced by the genotype; the expression of genes. |
| Population | All the individuals of one kind in a specified area at one time. |
| Punnett Square | A mathematical model that predicts the probability of possible genotypes and the phenotypes resulting from a genetic cross. |
| Recessive | A form of a gene that is expressed only when a dominant allele is not present. |
| Trait | The specific way a feature is expressed in an individual organism; for example, blue and green eyes are traits for eye color. |
| Variation | The range of expression of a trait within a population. |
