Sometime in the 18th or 19th century, a woman who carried the allele responsible for Huntington’s moved to the area and had 10 children. Many of the current residents of Lake Maracaibo region of Venezuela are descended from her. This is an example of bottleneck effect.

Environmental factors most affect the expression of __________.

Recessive illness causing alleles persist in heterozygotes in a population.

Characteristics shared by adopted children and their biological parents are mostly ____ while their similarities with adoptive parents reflect ____ influences.

Bottlenecks are detrimental to the viability of a species because of the loss of genetic diversity and the potential risk for inbreeding and the expression of recessive genetic traits.

Bonus: The breeds of dogs is an example of artificial selection.

Human height in a population varies continuously in a bell shape distribution. ____________ and ______________ are strong environmental factors in expressing genetic potential for height.

Development of antibiotic resistant strains of pathogenic bacteria such as MRSA is due to evolution of the non-resistant strains to resistant strains.

Alleles that are both expressed in a heterozygote are _____.

_______________ traits are determined by more than one gene, with each gene providing a small, but additive effect.