Wild-type E. coli grow best at 37 but can grow efficiently up to 42 . An E. coli strain has a mutation of the sigma subunit that results in an RNA polymerase holoenzyme that is stable and transcribes at wild-type levels at 37 . The mutant holoenzyme is progressively destabilized […]

You have been tracking a population of birds in the jungle and over several generations observed the following genotype frequencies for a given locus, B : 12% BB, 28% Bb, and 60% bb. The climate changed abruptly and resulted in the death of all homozygous recessive birds. In the next […]

Coming from the acid pH of the stomach which pH levels does the chime find when it enters the duodenum? Why is it necessary to maintain that pH level in the small intestine? What are the organs responsible for the pH level and how is it kept? After digestion the […]

1. Compare and contrast the characteristics of the ideal tissue forming the outer surface of the body with that forming the lining of the small intestine. How are they similar and different? What tissues fulfill these needs? 2. If a bone is broken, it will heal in several months. If […]