Question

How many meiotic divisions are essential in formation of 100 seeds in Cyperaceae family:
a. 100
b. 125
c. 150
d. 200

Answer 1

Hint: The Cyperaceae family is the family of grass-like monocotyledonous flowering plants. In this family for the production of one functional microspore (pollen grains) one meiotic division is required. Similarly, for the production of one functional megaspore one meiotic division is required. Seeds are formed by the fusion of microspores and megaspores.

Complete answer:
- In a flowering plant, when an ovule is fertilized by pollen resulting in the formation of a zygote which later develops into an embryo and the seed coat develops from the integuments.
- The microspores (pollen grain) are developed by the meiotic division. For the development of one microspore, one meiotic division is required. So, for the development of 100 microspores 100 meiotic division is required.
- The megaspore (ovule) is also developed by the meiotic division. For the development of one megaspore one meiotic division is required. So, for the development of 100 megaspores 100 meiotic division is required.
- So, by the fusion of 100 microspores and 100 megaspores, 100 seeds are formed.
- Hence for the 100 seed production 200 meiotic division takes place in the Cyperaceae family.

Hence, the correct answer is option (D).

Additional information:
Members of the Cyperaceae family show the irregular or unusual type of microsporogenesis (production of pollen grains) in which there is a formation of an asymmetrical tetrad. In megasporogenesis, there is a production of megaspore, and megaspores are developed into embryo sac during the process of megagametogenesis.

Note: For the production of 100 microspores like pollen grains and 100 megaspores like eggs in a member of family Cyperaceae, 200 meiotic divisions occur where 100 is present in each anther and carpel.