Why is it advantageous for a repressor like the lac repressor to be inactivated by binding to allolactose rather than by proteolytic cleavage? Match the words in the left column to the appropriate blanks in the sentences on the right. Proteolytic cleavage is used to inactivate repressors in an essentially process, such as in activation of a viral reproduction program. Repressor inactivation by binding a small molecule allows for changes in gene expression under conditions where concentrations of metabolites in the medium might be, and it the wasteful degradation and resynthesis of regulatory proteins.

Nephrons, the functional unit of kidneys, are responsible for formation of urine. the sentences describe situations that are the result of problems in the urine formation process. for the nephron shown below, match each situation to the step in the urine formation process where the problem lies.

The (blank) states that all loving things are made of cells.

Which of the following statements is correct in hour our immune system responds to a potential pathogen? a. the adapted immune system will call on the innate immune system to destroy the pathogen. b. b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c. the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. d. the t-cells in the adapted immune systems are the first to recognize the pathogen vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a. antigen, antibody b. antibody, antigen c. antibody, antibiotic d. antibiotic, antibody