Answer : (c)

Answer : (b)

Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening, self-pollinating flowers. Answer : (b)

Type of entry of pollen tube - 1)porogamy-micropyle 2)chalazogamy-chalazal 3)mesogamy-integument Answer : (d)

Female fig wasps help in pollination in Ficus. They enter the Ficus via ostiole, sub-closed inflorescences to lay their own eggs and during this time pollen gets to stick to the body of wasp and thus pollination occurs. Answer:(d)

Pollen grain can be cryopreserved in liquid nitrogen ( temp – 196°C) and used as pollen banks. Answer:(a)

Answer:(d)

The wings on the pollen grain aid in the dispersal of the pollen grains by the wind. Mango pollinators include different kinds of wasps, flies, stingless bees and even ants. mustard is basically an insect-pollinated type of crop, with ample pollen and nectar to attract pollinating insects. Cycas pollen is dry, light and round and pollinated by wind. Whereas, in pinus, pollen is winged that helps in pollination. Answer:(d)

(i) Pollenkitt is a hydrophobic mixture of materials, composed mainly of saturated and unsaturated lipids, carotenoids, flavonoids, proteins and carbohydrates. Statement (i) is correct. (ii) Microsporogenesis is the process of formation of pollen grains (microspores) from the sporogenous tissue. Microgametogenesis is the process of formation of male gametes from the generative cell nucleus that is present inside the pollen grain through mitosis. It occurs during dehiscence of pollen. Statement (ii) is correct. (iii) In calotropis and orchids, the pollen of each anther lobe formed a characteristics mass called pollinium. Statement (iii) is correct. (iv) In bisporic development instead of four, two megaspores are produced as a result of meiosis in the megaspore mother cell. Each megaspore has two haploid nuclei. One of these degenerates, the other undergoes megagametogenesis to form the embryo sac. It is also called the Allium type of embryo sac. statement (iv) is incorrect. Answer:(c)

Plumose stigma means feathery or hairy stigma. Such stigma is an adaption for wind pollinated flowers i.e. anemophily, as it can move due to wind to catch pollen carried by wind. Assertion and reason are false. Answer:(d)

Answer:(c)

Three cells are grouped together at the micropylar end and constitute the egg apparatus. The egg apparatus consists of two synergids and one egg cell. Answer:(c)

Two male gametes are discharged into embryo sac through pollen tube. One of the male gametes fuse with the egg, resulting in the production of diploid zygote. This is called syngamy or also called generative fertilization. The second male gametes fuses with two polar nuclei, producing a triploid primary endosperm nucleus. This is called triple fusion and is also known as vegetative fertilization. Answer:(d)

The second male gametes fuses with two polar nuclei, producing a triploid primary endosperm nucleus. This is called triple fusion and is also known as vegetative fertilization. In an embryo sac there occur two sexual fusion – one in syngamy and other in triple fusion. This phenomenon is called double fertilization. Answer:(b)

Herkogamy : It is the presence of natural or physical barrier between androecium and gynoecium which help in avoiding self pollination. In calotropis stignui, gynoecium is fused with pollinium and form gynostegium. Answer:(b)

Meroblastic embryogeny is common in gymnosperms. When the part of zygote is involved in the development of embryo, this type of embryo development is called meroblastic embryogeny. In these plants embryo is developed from a portion of oospores and in such case more than two embryos can be developed(polyembryony) Answer:(b)

Protandry: Anthers mature earlier. E.g, Salvia, clerodendron, sunflower, rose Answer:(a)

The phenomenon of having more than one embryo is called polyembryony. Formation of additional embryos from different parts of ovule like synergids, antipodal, nucellus, integuments etc. Example – Citrus, groundnut, onion, opuntia, mangifera. Answer:(a)

female gametophytes are part of gametophyte and ploidy is n. megaspore mother cells are part of sporophyte so these are diploid cells and their ploidy is 2n The synergids are haploid cells and their ploidy is n. Endothecium is a layer of diploid cells and their ploidy is 2n. Nucellus(located within the integumentary) have 2n ploidy. The integument is the outer protective envelope of an ovule. It is diploid in a diploid angiosperm. and their ploidy is 2n. Answer:(b)

The ovule is attached to placenta by means of a stalk called funiculus or funicle. The point of attachment of funicle to the ovule is known as hilum. Answer:(d)

In family asclepiadaceae and orchidacae, all the microspores in a sporangium adhere together in a single mass called pollinium. In calotropis and orchids, the pollen of each anther lobe formed a characteristics mass called pollinium. Answer:(a)

The key difference between quiescence and dormancy is that quiescence is the inability of a normal, non-dormant seed to germinate because of the absence of conditions suitable for germination while dormancy is an evolutionary adaptation that prevents seeds from germinating during unsuitable ecological conditions that would typically lead to a low probability of seedling survival. Orthodox seeds are seeds which will survive drying and/or freezing during ex-situ conservation. Perennials seeds are seeds that persist for many growing seasons. Answer:(a)

100 seeds of pea would be produced from 100 pollen. grains and 100 embryo sacs- 100 pollen grains will be formed by 25 microspore mother cells, while 100 embryo sacs will be formed by 100 megaspore mother cells Thus, number of meiotic divisions required to produce 100 seeds would be 125 number of meiotic divisions required to produce 10 seeds would be 12.5 or 13 Answer:(c)

Answer:(d)

Answer:(b)

Fertilization is defined as the fusion of male and female gametes to form the zygote which eventually develops into an embryo. Two male gametes are discharged into embryo sac through pollen tube. One of the male gametes fuse with the egg, resulting in the production of diploid zygote. This is called syngamy or also called generative fertilization. The second male gametes fuses with two polar nuclei, producing a triploid primary endosperm nucleus. This is called triple fusion and is also known as vegetative fertilization. In an embryo sac there occur two sexual fusion – one in syngamy and other in triple fusion. This phenomenon is called double fertilization. Answer:(d)

(i) The vegetative cell is bigger, has abundant food reserve and a large irregularly shaped nucleus. statement (i) is incorrect. (ii) The generative cell divides mitotically to give rise to the two male gametes before pollen grains are shed (3-celled stage). Statement (ii) is incorrect. (iii) In some cereals such as rice and wheat, pollen grains lose viability within 30 minutes of their release. Statement (iii) is correct. (iv)in some members of Rosaceae, Leguminoseae and Solanaceae, they maintain viability for months. Statement (iv) is incoreect. (v) The branch of study of pollens is called palynology. Statement (v) is correct. Answer:(d)

Answer:(d)

Remains of second cotyledons occurs in some grasses (monocot embryology). It is called epiblast. Answer:(c)

Non-endospermic or ex-albuminous: Food stored in endosperm is completely exhausted by developing embryo. Example : Seed of gram, pea, bean, orchid. Ricinuscommunis, Triticum aestivum and Oryza sativa possess endospermic seeds. Glycine max possess endospermic seed. Answer:(c)

The synergids have special cellular thickenings at the micropylar tip called filiform apparatus, which play an important role in guiding the pollen tubes into the synergid. Degenerated synergid is that synergid which starts degenerating at the time of pollination and its secretions attract the pollen tube towards micropyle. Persistent synergid is the other synergid that persists and starts degenerating at the time of fertilisation. Answer:(b)

Cleistogamy: The flowers remain close so there is no alternative self pollination. Examples: Pisum, Lathyrus, commelina, benghalensis. Answer:(d)

Entomophily ( Insect pollination) characteristics: (i) Flowers are coloured. Bluish-purplish – violet – yellow flowers attracts bees while reddish flowers attract butterflies and wasps. (ii) Flowers commonly posses an aroma or scent. (iii) Visiting insects are fed by either nectar and pollen. (iv) Pollen grains are sticky due to pollenkitt. (v) Stigmas are sticky. Answer:(b)

Wall of the ovary forms fleshy or dry fruit wall called pericarp. Perisperm is the nutritive tissue surrounding the embryo in certain seeds and developing from the nucellus of the ovule. Answer:(d)

Answer:(c)

endosperms in angiosperms are predominantly triploid (3n). but Pinus is exception. in pinus roots are generally diploid i.e 2n= 12. and endosperm is haploid i.e n therefore number of chromosome in endosperm is 6 Answer:(d)

Water lily and water hyacinth are pollinated by insects or wind. Answer:(b)

The fusion of one sperm with the egg cell to form the embryo and of the other sperm with the polar fusion nucleus to give rise to the endosperm ('double fertilization') was discovered by Nawaschin in 1898 in the liliaceous plants, Lilium martagon and Fritillaria tenella. Answer:(c)

Apogamy is formation of sporophyte or embryo directly from cells of gametophyte. One of the male gametes fuse with the egg, resulting in the production of diploid zygote. This is called syngamy. Statement (ii) is false. The point of attachment of funicle to the ovule is known as hilum. A raphe ( ridge) is formed by the fusion of funiculus with the body of ovule. statement (iv) is false. The layer below the epidermis later becomes the endothecium. Endothecium – Second wall layer usually single layered. Cells have a cellulose thickening with a little pectin and lignin. It help in anther dehiscence. Statement (i) is true. Synergids are produced by the mitotic division in the haploid megaspore of a diploid plant. So synergids of a diploid plant are haploid. Statement (iii) is true. Answer:(d)

Integuments of ovule forms seed coat. Outer integuments form testa and tegmen develops from inner integuments. The single cotyledon of monocots is called scutellum. In a monocotyledonous seed, the endosperm is separated from the embryo by a distinct layer is aleurone layer. The Aleurone layer is present in the monocotyledonous endospermic seed. It surrounds the endosperm. This layer is one cell thick. Answer:(c)

In some cereals such as rice and wheat, pollen grains lose viability within 30 minutes of their release, and in some members of Rosaceae, Leguminoseae and Solanaceae, they maintain viability for months. Answer:(d)

Answer:(c)

Apomixis is the asexual production of seeds so that apomictic seeds are clones of the mother plant. Advantage of apomictic seeds to farmer: It reduces the cost of hybrid production. There is no segregation of characters in the hybrid progeny. It helps the farmer to keep using the hybrid seeds to raise new crops each year. Answer:(c)

Pollen grains are rich in nutrients. Pollen consumption has been claimed to increase the performance of athletes and race horses. Pollen grains of many species cause severe allergies and bronchial afflictions in some people often leading to chronic respiratory disorders– asthma, bronchitis, etc. These statement are true. Parthenium or carrot grass that came into India as a contaminant with imported wheat, has become ubiquitous in occurrence and causes pollen allergy. Option (d) is false. Answer:(d)

Ploidy of aleurone layer is 3n. 3n = 24 that implies n is 8. Primary endosperm cell is triploid i.e. 3n. Thus, it has 24 chromosomes. Synergid cell is haploid i.e. n. Thus, It has 8 chromosomes. Nucellus cell is diploid i.e., 2n. Thus it has 16 chromosomes. Answer:(b)

The formation and differentiation of microspore is called microsporogenesis. The PMCs divide meiotically each forming generally tetrahedral tetrads. Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. For example, plants produce gametes through mitosis in gametophytes. Answer:(c)

In flowering plants, pollen grain arefirst cells of male gametophyte. Assertion is true. The process of formation of microspores from a pollen mother cell (PMC) through meiosis is called microsporogenesis. The microspores, as they are formed, are arranged in a cluster of four cells–the microspore tetrad. As the anthers mature and dehydrate, the microspores dissociate from each other and develop into pollen grains. Reason is true and correct explanation of assertion. Answer:(a)

Remains of second cotyledons in monocot embryo is called epiblast. Answer:(c)

In over 60 per cent of angiosperms, pollen grains are shed at this 2-celled stage. In the remaining species, the generative cell divides mitotically to give rise to the two male gametes before pollen grains are shed (3-celled stage). In the seed plants (gymnosperms and angiosperms), the sporophyte is green and photosynthetic and the gametophyte depends on the sporophyte for nourishment. Within the seed plants, the gametophyte has become further reduced, with fewer cells comprising the gametophyte. Plants use two abiotic (wind and water) and one biotic (animals) agents to achieve pollination. Majority of plants use biotic agents for pollination. Answer:(b)

Autogamy: It is a self pollination which occurs between anther and stigma of the same flower. Geitonogamy: It is transfer of pollen grain from anther of one flower to stigma of another flower of same plant or genetically similar plants. Since flowers are unisexual, it prevents autogamy but there is possibility of pollination between flowers of same plant. Answer:(d)