A mutation (Mutation A) in the lac operon of E. coli leads to an inability to ferment lactose, and the expression of the operon is always off. Introduction into the mutant of an F' factor containing the wild type lac operon does NOT restore the ability to ferment lactose, i. e., there is no expression of the operon from the plasmid either. a. What is the probable nature of Mutation A

Autotrophs a. consume their food to get energy b. may use photosynthesis to gain energy c. are also called consumers d. cannot use solar energy

What is the difference between the conducting zone and the respiratory zone of the respiratory system? the conducting zone is a series of cavities and tubes that move air to the respiratory zone where gases exchange with the bloodstream. the conducting zone exchanges gases between the lungs and the alveoli and the respiratory zone is a series of cavities and tubes that move air to the conducting zone. the conducting zone moves oxygen into the cells and the respiratory zone takes carbon dioxide away from the cells. the conducting zone moves oxygen into the bloodstream and the respiratory zone takes carbon dioxide away from the bloodstream.

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere, b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify, d)anaerobic bacteria kept thriving with more oxygen