| A | B |
|---|
| An Austrian monk whose study of garden peas earned him the title Father of Genetics | Gregor Mendel |
| The study of heredity | Genetics |
| The passing of traits from one generation to the next | Heredity |
| A section of DNA that determines a specific trait, such as eye color | Gene |
| Different variations of the same gene; for example, blue and brown are different alleles for eye color | Alleles |
| A trait that is expressed over another trait | Dominant |
| A trait that can be hidden by another trait | Recessive |
| The combination of alleles for a particular trait | Genotype |
| Having two of the same alleles for a trait | Homozygous (or pure) |
| Having two different alleles for a trait | Heterozygous (or hybrid) |
| The physical characteristics of an organism that show how genes are expressed | Phenotype |
| A natural law explaining that alternative forms of a gene separate during the formation of gametes (sex cells); they do not mix to form a new trait | Law of Segregation |
| Crossing one trait from two parent organisms | Monohybrid cross |
| A diagram that shows all possible gene combinations for a cross | Punnett Square |
| All chromosomes except sex chromosomes (X and Y) | Autosomes |
| Genetic disease that is carried by a gene on an autosome | Autosomal disorder (or disease) |
| A person who has one recessive gene for a recessive genetic disease; will not display symptoms of the disease but can pass on the gene to offspring | Carrier |
| An autosomal recessive disorder that causes the bod to produce unusually thick, sticky mucus; decreases life-expectancy | Cystic fibrosis |
| An autosomal recessive disorder where a person is born without the enzyme to break down and use phenylalanine, an essential amino acid | Phenylketonuria (PKU) |
| A fatal autosomal recessive disease that causes fatty material to build up in the nerves and brain | Tay-Sachs |
| Studying two traits crossed from parent organisms | Dihybrid cross |
| A natural law that explains how traits are inherited independently of other traits | Law of Independent Assortment |
| Having alleles that do not have complete dominance so the resulting trait is a mix of two alternative traits; for example red snapdragons crossed with white snapdragons produce pink snapdragons | Incomplete dominance |
| Having two or more alleles that are equally dominant for a trait so that both traits are expressed; for example, roan cattle both have red hair and white hair (not pink) | Codominance |
| A genetic disease cause by a codominant gene | Sickle cell anemia |
| The one pair of X & Y chromosomes that determines gender | Sex chromosomes |
| Genes that are found on either the X or the Y sex chromosome | Sex-linked genes |
| A sex-linked disorder that is carried on the X chromosome | Color blindness |
| A sex-linked disease that is carried on the X-chromosome | Hemophilia |
| A diagram used by geneticists to chart a trait from one generation to another | Pedigree |
| Scientist who studied the role of chromosomes in heredity and who is noted for his contribution in discovering linked genes | Thomas Morgan |
| Having two dominant alleles for a trait | Homozygous dominant |
| Having two recessive alleles for a trait | Homozygous recessive |
| A natural law stating that a dominant allele will always mask a recessive allele | Law of Dominance |
| Characteristics; often physical qualities such as color, height, etc. | Traits |
| Homozygous organism that always produces offspring with identical traits | True-breeding |
| Crossing a true-breeding recessive organism with an organism of dominant phenotype but unknown genotype; helps to determine the unknown genotype as either homozygous dominant or heterozygous dominant | Testcross |
| An autosomal dominant disease that results in the death of brain cells | Huntington's Disease |
| Having three or more alleles that can determine four or more phenotypes; for example, human blood groups have four phenotypes determined by three different alleles | Multiple Alleles |
| Genes that are often inherited together because they are located close to one another on the same chromosome | Linked genes |
| A recessive disorder or disease caused by a defective gene on the X chromosome; the most common type of sex-linked disorder | X-linked recessive disorder |
