Sexual reproduction in flowering plants practice · Mixed difficulty

Option A (Opposite to micropyle) is correct because the chalazal pole is located at the opposite end of the ovule from the micropyle.

Option C (Aleurone layer) is correct because the aleurone layer is a proteinaceous layer that surrounds the endosperm in monocot seeds, separating it from the embryo.

The correct answer is C (Sunflower, Wolffia, Eucalyptus) because these are angiosperms where PEN is formed after fertilization.

Option A is the wrong statement because double fertilization is unique to angiosperms, not gymnosperms and monocotyledons.

The correct answer is D (All of these) because non-albuminous seeds lack a persistent endosperm, are also called exalbuminous, and typically have thick cotyledons that store the reserve food.

Option C (Male gametophyte) is correct because a pollen grain represents the immature male gametophyte in flowering plants.

Option C (Embryo sac) is correct because Chalaza, Nucellus, and Integument are all diploid (2n) tissues of the ovule, whereas the embryo sac is haploid (n) after meiosis.

The correct answer is Apospory because it involves the development of a diploid embryo sac from a nucellus cell without meiosis.

The correct answer is D (Fertilization of the egg and the central cell by two sperms brought by the same pollen tube) because double fertilization involves one sperm fertilizing the egg and another sperm fertilizing the central cell, both delivered by the same pollen tube.

Option A is correct because if the female parent produces unisexual flowers (female flowers), emasculation (removal of anthers) is unnecessary as the flower already lacks anthers.

Option A (160) is correct because each pollen mother cell (PMC) produces 4 pollen grains. Therefore, 40 PMCs will produce 160 pollen grains.

Option D (self-sterility – gloris) is correct because self-sterility is commonly observed in plants like Petunia, not typically associated with Gloriosa.

Option B (III,II,I,IV) is correct because gamete formation precedes transfer, which leads to zygote formation, and finally, embryo development.

Option D (Pollen grain) is correct because Nucellus, Embryo sac, and Micropyle are all parts of the ovule, while pollen grain is part of the stamen (male reproductive part).

Option D (Ploidy of funicle, nucellus and all cells of embryo sac are same) is the statement not true for an anatropous ovule because the ploidy levels of the funicle, nucellus, and cells of the embryo sac are not all the same.

Option A (Endosperm, cotyledons) is correct because albuminous seeds store food in the endosperm, while non-albuminous seeds store food in the cotyledons.

Option D (Both (a) and (c)) is correct because the filiform apparatus of synergids guides the pollen tube into the embryo sac and is located near the micropylar end.

Option D (Pentaploid) is correct because the endosperm is formed by the fusion of two polar nuclei (4n + 4n) and one sperm (2n), resulting in 6n, but since the question states tetraploid female plant, it should be 2n + 2n + n = 5n.

Option B (Haploid) is correct because the egg apparatus consists of the egg cell and synergids, which are all haploid (n).

Option D (Angiosperms) is correct because double fertilization, involving the fusion of one sperm with the egg and another with the polar nuclei, is a unique characteristic of angiosperms.

Option B (Anemophily) is correct because anemophily refers to the dispersal of seeds by wind.

Option C (21) is correct because the synergid is a haploid cell (n), and if the root has 42 chromosomes (2n), then n = 21.

Option C (10, 20) is correct because the vegetative cell of pollen grain is haploid (n) and the nucellus cell is diploid (2n).

Option C (16) is correct because the root cell is diploid (2n) and the endosperm cell is triploid (3n). Therefore, if 3n = 24, then n = 8 and 2n = 16.

Option D (Pollen grain) is correct because Micropyle, Embryo sac, and Nucellus are all parts of the ovule, while pollen grain is part of the stamen (male reproductive part).

Option B (Central cell) is correct because the central cell is the largest cell in the ovule.

Option B (Nutritive) is correct because the tapetum's primary function is to provide nourishment to the developing pollen grains.

Option A (Genetic recombination) is correct because sexual reproduction involves the fusion of gametes, leading to the mixing of genetic material and thus genetic recombination.

Option D (Coleoptile) is correct because the coleoptile is a protective sheath covering the young shoot in grasses like wheat.

Option B (FALSE) is correct because microspores are arranged in a cluster of four cells called a microspore tetrad, not a megaspore tetrad.