51. Which of the following is responsible for phosphate solubilization?
A. Streptococcus
B. Streptomyces
C. Bacillus
D. Clostridium
52. Phosphate deregulated mutants are
A. less sensitive to phosphate regulation
B. moderately sensitive to phosphate regulation
C. highly sensitive to phosphate regulation
D. none of these
53. The mechanism of passive or facilitated diffusion requires
A. metabolic energy
B. concentration of solute against an electrochemical gradient
C. accumulation of solute against an electrochemical gradient
D. accumulation or concentration of solute against an electrochemical gradient
54. Nitrogen fixation is a process that requires
A. energy
B. an anaerobic environment
C. both (a) and (b)
D. an aerobic environment
55. Bacteriochlorophyll differs from chlorophyll in what way?
A. The chelated metal in bacteriochlorophyll is not Mg
B. There are chemical differences between the two chlorophyll in their side (R) groups
C. They have different absorption spectra
D. Both (b) and (c)