Question

Read the passage and answer the following questions:

The following graphs show the growth of two closely related species of paramecia, both when grown alone (Figure 1) and when grown together (Figure 2). Both species consume bacteria as their food source and reproduce by binary fission as often as several times a day.

Figure 1

Figure 2

The data in Figure 2 indicate that

• A. P. aurelia is preying on P. caudata.
• B. P. aurelia is a better competitor than P. caudata.
• C. P. aurelia and P. caudata are in a symbiotic relationship.
• D. P. aurelia is a parasite of P. caudata.
• E. P. aurelia grew better when combined with P. caudata than it did when grown alone.

Answer 1

The correct option is B P. aurelia is a better competitor than P. caudata.

Same species have common requirement of natural resource and act as a competitor of each other. Figure 2 clearly shows that P. aurelia is a better competitor than P. caudata. Both species consume bacteria as a food source. Symbiotic association benefit both partners, here, only P. aurelia is showing better growth rate while P. caudata growth rate is diminished highly when cultured together. P. aurelia grew better when grown alone.

Therefore, the correct answer is option B.