Question

a scientist wants to grow some bacteria on agar in a petri dish. she transfers a sample of the cells to the agar and counts the number of cells in the dish over time. the graph shows how the number of bacteria cells changed over time.question #3what life process is occurring in the bacteria as the number of cells increases from region a to region b?a a single bacterial cell is increasing in size over time.b the bacteria population is growing because each individual cell is increasing in size or getting larger.c the bacteria population is growing because each bacterial cell is reproducing asexually.d the bacteria population is developing from more cells to less cells.question #4why does the graph show the numbers of bacteria cells leveling off in region c?a the bacteria cells are beginning to die because of exposure to an antibiotic.b the bacteria population is stabilizing because the carrying capacity has been reached.c there is no more space on the graph to show the number of bacteria cells continuing to rise.d there are no limiting factors to cause the population to continue growing.

Explanation:

For Question #3:

• Option A is incorrect because the increase in cell count refers to population growth, not a single cell increasing in size.
• Option B is incorrect because population growth in bacteria comes from reproduction, not individual cells growing larger.
• Option C is correct because bacteria reproduce asexually (e.g., binary fission), which leads to a rapid increase in population size as seen from region A to B.
• Option D is incorrect because the graph shows an increase in cell numbers, not a decrease.

For Question #4:

• Option A is incorrect because the graph shows stabilization, not a decline that would indicate cell death from antibiotics.
• Option B is correct because region C represents the carrying capacity of the petri dish, where resources (nutrients, space) are limited, so the population stabilizes.
• Option C is incorrect because the leveling off is due to biological limits, not graph space.
• Option D is incorrect because limiting factors (resource scarcity) are the reason the population stops growing.

Answer:

Question #3: C. The bacteria population is growing because each bacterial cell is reproducing asexually.
Question #4: B. The bacteria population is stabilizing because the carrying capacity has been reached.