Answer:(a)

Answer : (c)

Answer:(b)

Answer:(c)

Answer:(c)

Answer:(b)

Answer:(a)

Answer:(c)

Answer:(a)

Answer:(c)

Answer:(d)

Answer:(a)

Answer:(a)

Answer:(b)

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Answer:(c)

Answer:(d)

Following are the post-fertilisation changes. Ovule → Seed Ovary→ Fruit Zygote → Embryo Central cell → Endosperm Answer : (d)

The phenomenon in which female gamete develops into embryo without getting fused with male gamete (fertilisation) is called parthenogenesis. Answer : (d)

Answer : (d)

prothallial cells: one of the cells produced by the first division of the microspore in a gymnosperm and believed to be a vestige related to the fern prothallus The flowering plants, also known as angiosperms, In angisperms Now the nucleus undergoes mitosis giving rise to two daughter nuclei. Out of the two cells so formed, the smaller one is called generative cell and the larger one is called vegetative cell. Vegetative cell has plenty of cytoplasm which has reserve food for the development of male gametophyte. Answer : (d)

In Gloriosa superba, flower structure is such that inspite of being bisexual the pollen grains are not able to reach the stigma. The anther dehisce outwardly at a distance from the stigma and therefore, pollen can't fall on the stigma and self-pollination is prevented. This adaptation by Gloriosa to prevent self-pollination by means of floral barriers is called Herkogamy. Heterostyly The condition of flowering plants in which flowers of the same species have styles of different lengths, so that the stigma is positioned below the anthers in some flowers and above them in others. This ensures that pollinating insects are more likely to transfer pollen from the anther of one flower to the stigma of another, thus promoting cross-pollination. Species showing heterostyly include the primrose pollen can't fall on the stigma and self-pollination is prevented. This adaptation by Gloriosa to prevent self-pollination by means of floral barriers is called Herkogamy. self-sterility The condition found in many hermaphrodite organisms in which male and female reproductive cells produced by the same individual will not fuse to form a zygote, or if they do, the zygote is unable to develop into an embryo. In plants this is usually termed self-incompatibility Cleistogamy is the self pollination occurring in an unopened flower.Self-pollination in this case is the transfer of pollen grains from anther to the stigma of the same flower which is unopened. Answer : (c)

Bees play a big role in agriculture. They pollinate crops, increase yields, and give rise to a lucrative honey industry. Bees are so important, in fact, that millions are spent renting hives to pollinate farmers' crops. Over one third of the food we eat relies on pollination by bees, either directly or indirectly. Answer : (b)

The central cell of a mature angiospermic embryo sac contains two polar nuclei. The two polar nuclei get fused prior to fertilisation to form a diploid secondary nucleus. Hence, the central cell is binucleate. Answer : (b)

Sporopollenin is one of the most chemically inert biological polymers. It is a major component of the tough outer (exine) walls of plant spores and pollen grains Answer : (d)

Endosperm is the triploid tissue in a fertilized ovule. The triploid condition is achieved by the fusion of two polar nuclei and one nucleus of a male gamete. So option (a) is correct. Answer : (a)

The remnants of nucellus which persists in some seeds is called perisperm. Answer : (d)

The male gametes of angiosperms consist of two sperm cells within a pollen grain or a pollen tube. They are derived from a single generative cell, which is formed as the smaller cell by unequal cell division in the microspore after meiosis. Answer : (b)

Diploid is a cell or organism that has paired chromosomes, one from each parent. Secondary nucleus the nucleus formed by the fusion of two polar nuclei in the embryo sac of a seed plant prior to fertilization Answer : (b)

In the intraspecific incompatibility fertilization if prevented between gametes which originate from same individual and some other individuals of the same species The top ten methods to overcome incompatibility. The methods are: 1. Mixed Pollination 2. Bud Pollination 3. Styler Pollination 4. Intraovarian Pollination 5. Test tube Pollination 6. Treatment of Style with Heat 7. Irradiation 8. Treatment with Chemicals 9. Use of CO2 10. Parasexual Hybridization. Mixed Pollination: In this technique the stigma is pollinated with incompatible and chemically treated compatible pollen. Answer : (a)

Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening, self-pollinating flowers. Especially well known in peanuts, beans and peas. This behaviour is wide spread in the grass family. Answer : (c)

An integument is a protective cell layer surrounding the ovule. The integuments develop into the seed coat when the ovule matures after fertilization. Answer : (b)

The suspensor functions early in embryogenesis to provide physical support, nutrition, and growth regulators to the developing embryo proper. The first cell of the suspensor towards the micropylar end becomes swollen and functions as a haustorium. The haustorium has wall ingrowths similar to those of a transfer cell. The last of the suspensors at the end of the embryo is known as hypophysis. Hypophysis later gives rise to the radicle and root cap. Answer : (b)

The male gametes of angiosperms consist of two sperm cells within a pollen grain or a pollen tube. Answer : (d)

Answer:(c)

A typical angiosperm embryo sac, at maturity, though 8-nucleate is 7-celled. At the time of fertilization, the female gametophyte has 3 antipodal cells + 2 synergids + 1 egg cell + 1 central cell, which equals 7-celled structure. But the central cell has 2 polar nuclei, which makes it 8-nucleate. Therefore, at maturity, the gametophyte is 7-celled and 8-nucleated. Answer : (a)

The zygote divides to form two cells: the upper cell (terminal cell) and the lower cell (basal cell). The fusion of one male gamete with egg and that of another male gamete with secondary nucleus is called as double fertilization. Answer : (c)

The chemical composition of sporopollenin Analyses have revealed a mixture of biopolymers, containing mainly long chain fatty acids, phenylpropanoids, phenolics and traces of carotenoids. Answer : (a)

The wall of the pollen mother cell (microspore mother cell) is deposited by callose (β-1, 3-glucan). Answer : (d)

The endosperm is triploid (with 3 sets of chromosomes) Hence, in the gametes the no. of chromosomes are 8. Answer : (a)

Syngamy is the permanent fusion of two individual cells (or gametes) to produce a unique organism (the zygote). This is also called sexual reproduction or fertilization Answer : (a)

Microspores are land plant spores that develop into male gametophytes, whereas megaspores develop into female gametophytes. Answer : (c)

statement 'a' is correct from figure below Statement 'b' is not correct apogamy the development of a plant without the union of gametes; development of a sporophyte from a gametophyte without fertilization. Fusion of nuclei of male and female gametes is called syngamy or fertilization. Statement 'c' is correct The synergids are part of the egg apparatus and are thought to help the pollen nucleus reach the egg cell for fertilization. The lower end of the embryo sac consists of the haploid egg cell positioned in the middle of two other haploid cells, called synergids. Statement 'd' is not correct The point at which funicle touches the ovule is known as hilum. Answer : (d)

The pollination of plants by bats is called chiropterophily. The blood-red flowers of the South African sausage tree (Kigelia pinnata) bloom at night on long, ropelike stalks that hang down from the limbs of this tropical tree. The fragrant, nectar-rich blossoms are pollinated by bats, insects and sunbirds in their native habitat. Pollination in Salvia, ophrys are usually bees, wasps, and flies, but many orchids also utilize moths, butterflies, fungus gnats, or birds to cross-pollinate their flowers Answer : (c)

The coconut water is free nuclear endosperm and the white kernel is the cellular endosperm. Answer : (a)

sunflower is a dicotyledonous plants, the number of cotyledons is two. Answer : (b)

Endosperm is formed by the repeated divisions of the primary endosperm nucleus Primary endosperm nucleus is formed by the fusion of male gamete with a diploid secondary nucleus. Answer : (c)

During the fertilization process, the pollen tube enters the female gametophyte by growing through the filiform apparatus and into one of the synergid cells Answer : (c)

Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening, self-pollinating flowers. Especially well known in peanuts, peas, and pansy this behavior is most widespread in the grass family. Answer : (d)