The number of microsporangia in a typical dithecous anther is:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Four
Explanation: The anther is a four-sided (tetragonal) structure consisting of four microsporangia located at the corners.
The term used for the embryo entering a state of inactivity is:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Dormancy
Explanation: The embryo may enter a state of inactivity called dormancy.
Which of the following is an example of albuminous seed?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Wheat
Explanation: Albuminous seeds retain a part of endosperm... e.g., wheat, maize, barley, castor.
In a fertilized embryo sac, the haploid, diploid and triploid structures are:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: A
Answer: Synergid, zygote and primary endosperm nucleus
Explanation: Synergids are haploid (n), Zygote is diploid (2n), and PEN is triploid (3n).
Panchanan Maheshwari was a distinguished botanist who specialized in which field?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Embryology
Explanation: Panchanan Maheshwari... rose to become one of the most distinguished botanists... He worked on embryological aspects and popularised the use of embryological characters in taxonomy.
The inner wall of the pollen grain, the intine, is composed of:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: Cellulose and pectin
Explanation: The inner wall of the pollen grain is called the intine. It is a thin and continuous layer made up of cellulose and pectin.
Pollen products are consumed by athletes and race horses primarily because:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: B
Answer: They are rich in nutrients
Explanation: Pollen grains are rich in nutrients... Pollen consumption has been claimed to increase the performance of athletes and race horses.
Which of the following plants has a single ovule in the ovary?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: D
Answer: Paddy
Explanation: The number of ovules in an ovary may be one (wheat, paddy, mango) to many (papaya, water melon, orchids).
Which of the following plants has many ovules in the ovary?
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Papaya
Explanation: The number of ovules in an ovary may be one... to many (papaya, water melon, orchids).
In a typical angiosperm ovule, the micropyle is formed by the absence of:
[Sexual-Reproduction-in-Flowering-Plants] [class-xii]
Correct Option: C
Answer: Integuments
Explanation: Integuments encircle the nucellus except at the tip where a small opening called the micropyle is organised.