Offspring that are the result of mating between two genetically different kinds of parents--the opposite of purebred. | hybrid |
The study of gene structure and action and the patterns of inheritance of traits from parent to offspring. This is the branch of science that deals with the inheritance of biological characteristics. | genetics |
A 19th century central European monk scientist who published his ideas about genetics in 1866 but largely went unrecognized until 1900, which was long after his death. He acquired his understanding of genetics mostly through pea plant breeding experiments. | Gregor Mendel |
A theory that inherited traits blend from generation to generation. Most of the leading scientists in the 19th century accepted it. However, Gregor Mendel proved that it was not correct. | blending theory |
Offspring that are the result of mating between genetically similar kinds of parents--the opposite of hybrid. | purebred |
Units of inheritance usually occurring at specific locations, or loci, on a chromosome. These units are responsible for hereditary characteristics in plants and animals. | genes |
Alternate forms of the same gene. Because they are different, their action may result in different expressions of a trait. | alleles |
The genetic makeup of an individual for a trait or for all of his/her inherited traits—not the observable or detectable characteristics. | genotype |
A genotype consisting of two identical alleles of a gene for a particular trait. | homozygous genotype |
A genotype consisting of two different alleles of a gene for a particular trait. | heterozygous genotype |
The observable or detectable characteristics of an individual organism; the detectable expression of a genotype. | phenotype |
The general term for an allele that masks the presence of another allele in the phenotype. | dominant allele |
The general term for an allele that is masked in the phenotype by the presence of another allele. | recessive allele |
Gregor Mendel's principle of genetic inheritance stating that, for any particular trait, the pair of genes of each parent separate (during the formation of sex cells) and only one gene from each parent passes on to an offspring. | principle of segregation |
Gregor Mendel's principle of genetic inheritance stating that different pairs of genes are passed to offspring independently so that new combinations of genes, present in neither parent, are possible. In other words, the distribution of one pair of alleles does not influence the distribution of another pair--the genes controlling different traits are inherited independently of one another. | principle of independent assortment |
A simple graphical method of showing all of the potential combinations of offspring genotypes that can occur and their probability given the parent genotypes. This system involves the use of a tic-tac-toe square. It was named after pioneer British geneticist. | Punnett square |
The term for a genotype in which there are two dominant alleles. | homozygous dominant |
The term for a genotype in which there is a dominant allele and a recessive one. | heterozygous |
The term for a genotype in which there are two recessive alleles. | homozygous recessive |
The genotype that normally results in the expression of a recessive allele in the phenotype. | homozygous recessive |
The only genotype that normally will not result in the expression of a dominant allele in the phenotype. | homozygous recessive |
The genotype of an individual who is a carrier for a recessive allele that is not expressed in his/her phenotype. | heterozygous |