Passage I

Bacteria reproduce by a process in which a single cell divides into two cells. The average time required for bacteria to divide and their population to double is called the generation time. Table 1 presents the generation time for a variety of bacteria at a given temperature.

Bacterial population growth occurs in a series of distinct steps referred to as a bacterial growth curve. It consists of 4 phases, which reflect changes in the cells' environment and metabolism over time. See Figure 1.

5. Which of the following hypotheses about bacterial populations is supported by the data presented in Figure 1 ?

Answer and Explanation

Your Answer is

Correct Answer is D

Explanation

The method of elimination. First exclude A, because the slope of the line segment is always changing, not change at a constant rate;

Exclude B, because it can be seen from the generation time in table 1 that it is not immediately;

p>C is also excluded, because it can be seen from figure 1 that there is a lag phase with a constant number first.