| A | B |
|---|
| allele | each member of a gene pair that determines a specific trait |
| amino acids | building blocks of proteins |
| chromosomes | rod-shaped structures found in the nucleus of every cell in an organism |
| deoxyribonucleic acid | molecule that stores and passes on genetic information from one generation to the next |
| DNA | deoxyribonucleic acid |
| dominant | trait that is expressed when two different genes for the same trait are present; "stronger" of two traits |
| genes | units of heredity; segments of DNA on chromosomes |
| genetic engineering | process in which genes, or pieces of DNA, from one organism are transferred into another organism |
| genes | study of heredity, or the passing on of traits from an organism to its offspring |
| genotype | gene makeup of an organism |
| hybrid | organism that has two different genes for a trait, or that combines traits of two different but related species |
| hybridization | crossing of two genetically different but related species of organisms |
| inbreeding | crossing plants or animals that have the same or similar sets of genes, rather than different genes |
| incomplete dominance | condition in which neither of the two genes in a gene pair masks the other |
| karyotype | chart that shows the size, number, and shape of all the chromosomes in an organism |
| meiosis | process of cell division in which sex cells (sperm and egg) are produced |
| mutagens | factors, such as radiation and certain chemicals, that cause mutations |
| mutation | sudden change in a gene or chromosome |
| nondisjunction | failure of a chromosome pair to separate during meiosis |
| phenotype | physical appearance |
| plasmid | ring of bacterial DNA |
| recessive | trait that seems to disappear when two different genes for the same trait are present; "weaker" of two traits |
| recombinant DNA | DNA that contains DNA from two different organisms |
| replication | process in which DNA molecules form exact duplicates |
| ribonucleic acid | nucleic acid that "reads" the genetic information carried by DNA and guides protein synthesis |
| RNA | ribonucleic acid |
| selective breeding | crossing of plants and animals that have desirable characteristics to produce offspring with those desirable characteristics |
| sex chromosomes | chromosomes that determine the sex of an organism; X and Y chromosomes |
| sex-linked traits | traits that are carried on the X chromosome |
| traits | physical characteristics |
