29) Matching

Inheritance of the ABO blood group type is an example of this type of inheritance.

Multiple-allele inheritance

Rare type of dwarfism resulting from an impaired ability of the fetus to lengthen long bones by endochondrial ossification.

Achondroplasia

Lack of skin pigmentation.

Albinism

Genes for the same trait that have different expressions.

Allele

Chromosomes regulating most body characteristics

Autosomes

Means by which genes trade places, some maternal and some paternal on each chromosome.

Chromosome crossover

Distribution of chromosomes to different gametes.

Chromosome segregation

A condition of drier excessively sticky mucus production.

Cystic fibrosis

The gene allele that suppresses or masks the expression of the other allele.

Dominant

The dominant gene is expressed when present; the recessive gene is expressed only in the absence of the dominant gene.

Dominant-recessive inheritance

Results in chromosomes that have mixed contributions from each parent.

Gene recombination

Actual genetic makeup

Genotype

Situation in which an individual has different alleles making up the genotype for a particular trait.

Heterozygous

Situation in which an individual has identical alleles for a particular trait.

Homozygous

An unremitting, fatal nervous system disease involving degeneration of the basal nuclei.

Huntington's disease

The heterozygote has a phenotype intermediate between those of the homozygous dominant and homozygous recessive.

Incomplete dominance

A particular gene's allele received by a gamete has no influence over selection of a different gene's allele.

Independent assortment

Inheritance that results in continuous or qualitative phenotypic variations between two extremes; an example is skin color.

Polygenic inheritance

Genes not expressed unless they are present in homozygous condition.

Recessive

A chromosome pair that may be very different in size.

Sex chromosomes

Inherited traits determined by genes on the X or Y chromosomes.

Sex-linked inheritance

A disorder of brain lipid metabolism.

Tay-Sachs disease