Question

1. what is the optimal ph range for most human pathogens? a) 1 - 3 b) 4 - 6 c) 6.5 - 7.5 d) 8.5 - 10 5. a bacterial culture that grows only at the bottom of a thioglycolate tube is classified as a(n): a) obligate aerobe b) facultative anaerobe c) aerotolerant anaerobe d) obligate anaerobe

Explanation:

For question 4, most human pathogens thrive in a near - neutral pH environment which is around 6.5 - 7.5. For question 5, obligate anaerobes cannot grow in the presence of oxygen and accumulate at the bottom of a thioglycolate tube where oxygen concentration is low.

Answer:

1. c) 6.5 - 7.5
2. d) Obligate anaerobe