FREE NEET Biology Practice MCQ Test: Sexual Reproduction In Flowering Plants Exercise 1 Questions Answers With Detailed Explanations [PDF]

Answer: (d)

Answer: (c)

Within the embryo sac three cells are grouped together at the micropylar end and constitute the egg apparatus. The egg apparatus, in turn, consists of two synergids and one egg cell. The synergids have special cellular thickenings at the micropylar tip called filiform apparatus, which plays an important role in guiding the pollen tubes into the synergid. Three cells are at the chalazal end and are called the antipodals. The large central cell, has two polar nuclei.

Answer: (c)

Answer: (d)

Answer: (c)

Answer: (d)

Exine is tough, cutinized layer often with spinous outgrowth but sometimes smooth. Exine is composed of sporopollenin which is resistant to physical and biological decomposition. It protect the pollens from environmental extremes.

Answer: (c)

Part of embryo axis between the plumule and cotyledonary node is epicotyl (above the level of cotyledons) while the part between radicle and cotyledonary node is called hypocotyl (below the level of cotyledons).

Answer: (b)

Answer: (a)

Answer: (a)

In angiosperms, the functional megaspore is the first cell of female gametophyte. It enlarges and undergoes three nuclear mitotic divisions to form embryo sac.

Answer: (c)

Apomixis is a reproductive process which does not involve gametic fusion. In apomictic flowering plants there is no fertilisation and embryos develop simply by division of a cell of ovule.

Answer: (a)

Each microspore or pollen is having a two layered wall. Outer layer is thick tough cuticularised called exine, which is chiefly composed of a material called 'sporopollenin'. Inner layer is thin, delicate and smooth called intine, which is made of pectocellulose. Exine is not uniform but is thin at one or more places in the form of germ pores. Whereas intine made of pectocellulose covers the entire surface of pollen grains.

Answer: (a)

Generative cell was destroyed by laser but a normal pollen tube was still formed because vegetative cell is not damaged. Each microspore divide by mitotic division making a smaller generative cell and a larger vegetative cell or tube cell. If generative cell is damaged then the normal pollen tube will be formed because pollen tube is formed by vegetative cell not by generative cell of microspore.

Answer: (d)

Answer: (c)

Answer: (b)

Sporogenous tissue is always diploid, endothecium is second layer of anther wall and performs the function of protection and help in dehiscence of anther to release the pollen. Hard outer layer of pollen is called exine but tapetum always nourishes the developing pollen. Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus (polypoid).

Answer: (a)

Answer: (b)

Answer: (c)

Grass is a monocot plant. Primary sporogenous cell gives rise to microspore mother cells or pollen mother cells. Each MMC on reduction division gives rise to 4 microspores or pollens and this formation of microspores or pollens is called microsporogenesis. Karyokinesis is of successive type. The successive type of cytokinesis is common in monocots. Here both meiotic I and II nuclear divisions are followed by wall formation and it leads to isobilateral tetrad.

Answer: (c)