Ch 14 - Mendel & the Gene Idea

An alternative form of a gene.

A technique for determining genetic abnormalities in a fetus by the presence of certain chemicals or defective fetal cells in the amniotic fluid, obtained by aspiration from a needle inserted into the uterus.

(CVS) A technique for diagnosing genetic and congenital defects while the fetus is in the uterus. A small sample of the fetal portion of the placenta is removed and analyzed.

A phenotypic situation in which both alleles are expressed in the heterozygote.

Having at least one common ancestor in the preceding few generations.

A phenomenon in which one gene alters the expression of another gene that is independently inherited.

The genetic makeup of an organism.

Having two different alleles for a given genetic character.

Having two identical alleles for a given trait.

The mating or crossing of two varieties.

A type of inheritance in which F1 hybrids have an appearance that is intermediate between the phenotypes of the parental varieties.

Mendel's second law, stating that each allele pair segregates independently during gamete formation; applies when genes for two traits are located on different pairs of homologous chromosomes.

Mendel's first law, stating that allele pairs separate during gamete formation, and then randomly re-form pairs during the fusion of gametes at fertilization.

The inheritance of a single character.

More than two possible alleles at a locus (The position of a gene on a chromosome).