Tay-Sachs disease is caused by an autosomal recessive allele. The disease is characterized by mental deficiency and blindness, with death occurring by four years of age. The incidence of the disease among newborns is about 10 per million births. Assuming Hardy-Weinberg equilibrium, estimate the frequency of the allele and of the heterozygotes.

Sampling lake water for microscopic organisms is not as easy as it sounds when you want to both count and identify species. in a given water sample, your bacteria of choice can be rare or difficult to culture, particularly given the mixture of bacteria in a biofilm. which of the following culture media would be best for growing fecal coliforms when they are relatively less abundant than other bacteria in the lake? anaerobic culture medium enrichment culture medium complex culture medium basic culture medium

Explain how you will prioritize tasks in the medical office by immediate, essential, or optional. how will you re-prioritize when disruptions occur?

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.