NEET UG 2012 — Botany Sexual Reproduction in Flowering Plants

How many meiotic and mitotic divisions need to occur for the development of a mature female gametophyte from the megaspore mother cell in an angiosperm plant?

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : A typical unfertilised, angiosperm embryo sac at maturity is 8 nucleate and 7-celled. Reason (R) : The egg apparatus has 2 polar nuclei. In the light of the above statements, choose the correct answer from the options given below :

Given below are two statements : One is labelled as Assertion (A) and other is labelled as Reason (R). Assertion (A) : Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus. Reason (R) : Presence of more than one nucleus in the tapetum increases the efficiency of nourishing the developing microspore mother cells. In light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Both wind and water pollinated flowers are not very colourful and do not produce nectar. Reason (R) : The flowers produce enormous amount of pollen grains in wind and water pollinated flowers. In the light of the above statements, choose the correct answer from the options given below:

Identify the set of correct statements: A. The flowers of Vallisneria are colourful and produce nectar. B. The flowers of water lily are not pollinated by water. C. In most of water-pollinated species, the pollen grains are protected from wetting. D. Pollen grains of some hydrophytes are long and ribbon like. E. In some hydrophytes, the pollen grains are carried passively inside water. Choose the correct answer from the options given below.