Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Dioecy ensures that outbreeding will always occur.
Reason R: In dioecy, male and female flowers are present on different parts of the same plant.

In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both A and R are correct and R is the correct explanation of A
• B. Both A and R are correct but R is NOT the correct explanation of A
• C. A is correct but R is not correct
• D. A is not correct but R is correct

Hint:

Distinguish these floral distribution terms:
- Monoecy: Male and Female flowers on the same plant (e.g., Maize). Prevents autogamy but not geitonogamy.
- Dioecy: Male and Female flowers on different plants (e.g., Papaya). Prevents both autogamy and geitonogamy.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Plants have evolved various morphological mechanisms (outbreeding devices) to prevent self-pollination and promote cross-pollination (outbreeding) to maintain genetic diversity.

Step 2: Detailed Explanation:
Let us analyze both statements:
Assertion A:
Dioecy is a condition where a plant species has distinct male and female individuals.
A single plant produces either exclusively male flowers or exclusively female flowers (e.g., papaya, date palm, spinach).
Because a single plant cannot self-pollinate, dioecy represents an obligate barrier to self-fertilization, ensuring that outbreeding (cross-pollination) always occurs.
Thus, Assertion A is correct.
Reason R:
In dioecy, male and female flowers are borne on different individual plants.
The condition where male and female flowers are present on different parts of the same plant is known as monoecy (e.g., maize, castor, coconut).
Therefore, Reason R is incorrect because it describes monoecy rather than dioecy.

Step 3: Final Answer:
Assertion A is correct, but Reason R is incorrect.
This corresponds to Option (C).