A variety of microorganisms live in the human digestive tract, especially in the small intestine. Their actions aid in digestion, and they help synthesize essential vitamins. What best describes the relationship between a human and the intestinal microorganisms?

A. parasitic symbiosis, because the microorganisms live on food that the human provides
B. mutualistic symbiosis, because all of the species benefit from the relationship
C. predator/prey, because the microorganisms live on food that the human provides
D. decomposition, because the bacteria live on dead or decaying organic matter

Approximately 90% of all cases of polycystic kidney disease are inherited in an autosomal dominant fashion. the disease is typically related to mutations to genes (pkd1 and pkd2). pkd genes can be found on chromosome 16. the disease occurs in approximately 1: 800 to 1: 1000 people. here is a hypothetical example. the dominant allele d will cause the development of pkd. the recessive allele is known as d. what genotypes would correspond to suffering from pkd? dd, dd what genotypes would correspond to being normal (not suffering from pkd)? dd consider that 1: 1,000 people have pkd in your population of 325million. consider that pkd is inherited in an autosomal dominant fashion. show you math for all of the following questions: what is the genotypic frequency for dd? what is the genotypic frequency for dd? what is the genotypic frequency for dd? what is p? what is q? how many people in your population would have pkd?