Which among the following statements are true for unisexual flowers?
Which among the following statements are true for unisexual flowers?
The correct option is B (ii), (iii) and (iv)
The correct option is B.
Explanation for correct option-
Statement (ii)- They possess either stamen or pistil.
Unisexual flowers either possess stamens (androecium) or carpels (gynoecium).
Statement (iii) - They show cross-pollination.
A unisexual flower does not show self-pollination as these flowers possess either stamen or carpel. Therefore, they show cross-pollination.
Statement (iv) - Unisexual flowers possessing only stamens cannot produce fruits.
Fruits are formed post-fertilization from the ovary, part of the carpel. Hence, unisexual flowers containing only stamens cannot produce fruits.
Explanation for incorrect options-
Option A:
Statement (i) - They always possess stamen and pistil.
Flowers that possess both stamen and pistil are called bisexual flowers. Unisexual flowers include either stamen or pistil only.
Statement (iv) - Unisexual flowers possessing only stamens cannot produce fruits.
The ovary (a part of the carpel) develops into fruits after fertilization. Hence, a staminate unisexual flower cannot form fruits.
Hence, this option is incorrect.
Option C:
Statement (iii) - They show cross-pollination.
A unisexual flower cannot show self-pollination as these flowers possess either stamen or carpel. Hence, such flowers show cross-pollination.
Statement (iv) - Unisexual flowers possessing only stamens cannot produce fruits.
Fruits are formed from the ovary after fertilization, and thus, a unisexual flower with only stamens cannot produce fruits.
This option is incorrect as statements (iii) and (iv) are not the only correct statements.
Option D
Statement (i) - They always possess stamen and pistil.
Bisexual flowers possess both stamen and pistil, whereas unisexual flowers only possess stamen or pistil.
Statement (iii) - They show cross-pollination.
A unisexual flower possesses either stamen or carpel. Therefore, they show cross-pollination, not self-pollination.
Statement (iv) - Unisexual flowers possessing only stamens cannot produce fruits.
After fertilization, the ovary in the carpel forms the fruits. Hence, unisexual flowers containing only stamens cannot produce fruits.
Hence, this option is incorrect.
Statements (ii), (iii), and (iv) are true for unisexual flowers.
(ii), (iii) and (iv)
The correct option is B.
Explanation for correct option-
Statement (ii)- They possess either stamen or pistil.
Unisexual flowers either possess stamens (androecium) or carpels (gynoecium).
Statement (iii) - They show cross-pollination.
A unisexual flower does not show self-pollination as these flowers possess either stamen or carpel. Therefore, they show cross-pollination.
Statement (iv) - Unisexual flowers possessing only stamens cannot produce fruits.
Fruits are formed post-fertilization from the ovary, part of the carpel. Hence, unisexual flowers containing only stamens cannot produce fruits.
Explanation for incorrect options-
Option A:
Statement (i) - They always possess stamen and pistil.
Flowers that possess both stamen and pistil are called bisexual flowers. Unisexual flowers include either stamen or pistil only.
Statement (iv) - Unisexual flowers possessing only stamens cannot produce fruits.
The ovary (a part of the carpel) develops into fruits after fertilization. Hence, a staminate unisexual flower cannot form fruits.
Hence, this option is incorrect.
Option C:
Statement (iii) - They show cross-pollination.
A unisexual flower cannot show self-pollination as these flowers possess either stamen or carpel. Hence, such flowers show cross-pollination.
Statement (iv) - Unisexual flowers possessing only stamens cannot produce fruits.
Fruits are formed from the ovary after fertilization, and thus, a unisexual flower with only stamens cannot produce fruits.
This option is incorrect as statements (iii) and (iv) are not the only correct statements.
Option D
Statement (i) - They always possess stamen and pistil.
Bisexual flowers possess both stamen and pistil, whereas unisexual flowers only possess stamen or pistil.
Statement (iii) - They show cross-pollination.
A unisexual flower possesses either stamen or carpel. Therefore, they show cross-pollination, not self-pollination.
Statement (iv) - Unisexual flowers possessing only stamens cannot produce fruits.
After fertilization, the ovary in the carpel forms the fruits. Hence, unisexual flowers containing only stamens cannot produce fruits.
Hence, this option is incorrect.
Statements (ii), (iii), and (iv) are true for unisexual flowers.
