Free Sexual Reproduction In Flowering Plants (Daily Quiz: 10) NEET Biology Questions & Answers with Detailed Explanation & Full Review

Answer: (c)

Female gametophyte is 7-celled structure. Out of these, three cells are grouped together at the micropylar end and constitute of two synergids and one egg cell, three antipodal cells are at the chalazal end and the large central cell.

Answer: (b)

Cotyledons and scutellum are two homologous structures in the embryo of a typical dicot and a grass. Cotyledon is an embryonic leaf in seed-bearing plants, one or more of which are the first leaves to appear from a germinating seed. Scutellum is the large shield like cotyledon of the embryo of certain monocots. It is specialized for the absorption of food from the endosperm.

Answer: (c)

Dioecy and self-incompatibility are the methods to prevent self-pollination in plants. In dioecy, male and female flowers are borne on separate plants. So, that cross-pollination is promoted. In self- incompatibility, pollens are prevented to fertilise the ovules of same flower by inhibiting pollen germination on the pistil.

Answer: (d)

Anatropous ovule is a completely inverted ovule turned back 180 degrees on its stalk. It is inverted at an early stage of growth, so that the micropyle is turned toward the funicle and the embryonic root is at the opposite end. In the given figure of anatropous ovule, the structure marked as A, B, C and D are respectively micropyle, nucellus, embryo sac and chalazal pole.

Micropyle is the opening through which pollen nuclei enter the ovule. Nucellus is the central part of an ovule, containing the embryo sac. Embryo sac is the female gametophyte of a seed plant, containing the egg, synergids, and polar and antipodal nuclei. Chalazal end is the basal part of a plant ovule opposite the micropyle; where integument and nucellus are joined.