Question

The egg-laying mammal, platypus, is known for its ability to inject venom by stabbing with spurs on its hindlimbs. Which one (or more) of the following statements supports the hypothesis that venom in this species is used for intrasexual competition?

• A. Only males produce venom.
• B. Venom is secreted only during the breeding season.
• C. Venom is only effective against invertebrates.
• D. Venom is ineffective against conspecifics.

Hint:

Intrasexual competition involves individuals of the same sex competing for mates. Males producing venom during the breeding season supports the idea that it is used to compete with other males.

Answer 1

The Correct Option is A, B

Intrasexual competition occurs when individuals of the same sex compete for access to mates. In this case, male platypuses produce venom, which is likely used during interactions with other males to establish dominance or fend off rivals.

Step 1: Analyzing the options.
- (A) Only males produce venom: This supports the hypothesis that venom is used for intrasexual competition, as only males produce it, possibly to gain an advantage over other males. - (B) Venom is secreted only during the breeding season: This also supports the hypothesis, as this timing aligns with the period of heightened male competition for mates. - (C) Venom is only effective against invertebrates: This does not support the hypothesis for intrasexual competition, as it suggests the venom is not used in male-to-male competition. - (D) Venom is ineffective against conspecifics: If venom were ineffective against other males (conspecifics), it would not be useful for intrasexual competition.

Step 2: Conclusion.
The correct answers are (A), (B), and (C), as they provide evidence that venom is used by males in intrasexual competition.

Final Answer: (A), (B)