Question

Choose the correct statements regarding population interactions between two species.
A. In both parasitism and commensalism, only one species benefits and the other species is harmed.
B. Both species benefit in mutualism.
C. Both species benefit in commensalism.
D. In parasitism, only one species benefits and the other species is harmed.
E. In amensalism, one species is harmed and the other is unaffected.
Choose the correct answer from the options given below :

• A. B and E only
• B. B, D and E only
• C. A and B only
• D. A and D only

Hint:

Logic Tip: Master the basic symbols: Mutualism: (+, +) Commensalism: (+, 0) Amensalism: (-, 0) Parasitism/Predation: (+, -) Competition: (-, -)

Answer 1

The Correct Option is B

Step 1 : Understanding the Question:
This question evaluates our knowledge of ecological population interactions. We need to identify the correct statements describing the outcomes (benefit, harm, or no effect) for the two species involved in mutualism, parasitism, commensalism, and amensalism.
Step 2 : Key Formulas and Approach:
The approach involves applying the standard biological symbols for interaction outcomes:
- Positive (+) = Benefit to the organism.
- Negative (-) = Harm to the organism.
- Zero (0) = Neutral or Unaffected.
Classification: Mutualism (+,+); Parasitism (+,-); Commensalism (+,0); Amensalism (-,0).
Step 3 : Detailed Explanation:

Statement A: In parasitism (+,-), one benefits and one is harmed. However, in commensalism (+,0), one species benefits while the other is unaffected. Therefore, the claim that harm occurs in both is incorrect.

Statement B: Mutualism (+,+) is defined as a relationship where both species derive a biological benefit from their association (e.g., fungi and algae in lichens). This statement is correct.

Statement C: In commensalism (+,0), only one species benefits, while the other remains completely unaffected. Claiming that both benefit describes mutualism, not commensalism. Thus, this statement is incorrect.

Statement D: Parasitism (+,-) is an interaction where one organism (the parasite) benefits at the expense of the other (the host), which is harmed by the loss of energy or tissue damage. This statement is correct.

Statement E: Amensalism (-,0) is a relationship where one species is inhibited or harmed (often through the release of chemicals), while the other species remains completely neutral or unaffected. This statement is correct.

Step 4 : Final Answer:
Upon detailed evaluation, statements B, D, and E are the only correct descriptions of population interactions. Therefore, the correct combination is found in option (B).