Question

Identify the wrong pair of statements.
 A) The number of stamens in 5 flowers of Allium is equal to those in 5 flowers of Solanum.
B) The microsporangia of Hibiscus and Asparagus are having 80 pollen grains each. Then the ratio of the number of pollen grains produced from each stamen of these two plants is 1: 1.
C) The ratio of the number of stamens in the flowers of Pisum and Datura is 2: 1.
D) The number of carpels in a flower of Smilax is equal to the number of carpels in a cyathium inflorescence.

Answer 1

Hint: Stamen is the male reproductive organ bearing microsporangia. The lobes of microsporangia contain pollen grains. The carpel is the female reproductive organ of a plant.

Complete answer:
Genus Allium includes plants like onion, garlic, chives and leek. They are flowering monocots. Whereas Solanum genus includes flowering plants like potato, tomato and eggplant. The number of stamens in Allium is 6 so in 5 flowers the total number of stamens is 30. The number of stamens in Solanum is 5 so in 5 flowers the total number of stamens is 25. The number of stamens in both the flowers is hence not equal. So, statement A is wrong.

Hibiscus is a dicot consisting of varying numbers of stamens whereas the number of stamens in asparagus is 6. So, the number of pollen grains produced in each stamen will not be the same, hence the ratio 1:1 is incorrect. Statement B is wrong.

Genus Pisum belongs to Family Fabaceae and its flower has 10 stamens. Datura belongs to Family Solanaceae and its flower has 5 stamens. The ratio of the number of stamens in both the flowers 10:5 will be 2:1. So statement III is correct. A Smilax flower has 3 united carpels and cyathium is a false flower forming an inflorescence (arrangement of flowers) with 3 carpels. The number of carpels is equal in both flowers. So, statement C is correct. Therefore, Statement A and B are wrong, which means the correct option for this question is C, i.e. Assertion is correct but the reason is incorrect.

Hence the correct option is C, The ratio of the number of stamens in the flowers of Pisum and Datura is 2: 1

Note: A stamen typically consists of a filament stalk and an anther containing microsporangia. A pollen grain in the microsporangium grows from a microspore and contains the male gametophyte. Typically, the number of stamens in a flower is a multiple of the number of members in a single whorl of the perianth. If a flower has 5 sepals and 5 petals, it may have either 5 stamens or 10 stamens.