Sexual reproduction in flowering plants practice · Medium

Option C (Seed coat) is correct because the integuments of the ovule develop into the protective outer layer of the seed, known as the seed coat or testa.

Option B (Geitonogamy) is the correct answer because it involves the transfer of pollen grains from the anther to the stigma of another flower of the same plant, differing from the other self-pollination mechanisms.

Option C (Endosperm , Ploidy : $2n$) is the mismatch because endosperm is triploid (3n), not diploid (2n).

Option C (Both (a) and (b)) is correct because endospermeogenesis (endosperm formation) and embryogenesis (embryo development) are the two main events that occur after fertilization.

The correct answer is D (One male gamete with egg and other with secondary nucleus) because double fertilization involves one sperm fusing with the egg to form the zygote and the other sperm fusing with the secondary nucleus to form the endosperm.

Option C (Both (a) and (b)) is correct because a seed is a ripened ovule and contains a plant part with two generations (the sporophyte embryo and the gametophyte tissue).

Option B (Diploid) is correct because a zygote is formed by the fusion of two haploid gametes, resulting in a diploid cell.

Option D (All of these) is correct because pollen grains can cause bronchial afflictions, asthma, and bronchitis due to their allergenic properties.

Option A (36) is correct because the endosperm is triploid (3n), and the microspore mother cell is diploid (2n). Therefore, n = 12, and 3n = 36.

Option D (Bilobed and tetrasporangiate) is correct because a typical angiosperm anther is bilobed, with each lobe containing two microsporangia, making it tetrasporangiate.

Option C (24000) is correct because each microspore mother cell produces 4 pollen grains, and the calculation is 10 flowers * number of stamens * 30 microspore mother cells * 4 pollen grains.

Option C (Angiosperms) is correct because double fertilization is a unique characteristic of angiosperms.

Option B (The outer integument of ovule develops into tegmen) is wrong because the outer integument develops into the testa, while the inner integument develops into the tegmen.

Option A (ZZ, AA) is correct because the endosperm is formed by the fusion of two polar nuclei (AA) and one sperm (Z), resulting in ZZA.

Option D (All of these) is correct because wind-pollinated pollens are typically non-sticky, light, and produced in large numbers to increase the chances of successful pollination.

Option D (Xenogamy) is correct because xenogamy involves the transfer of pollen grains from one plant to the stigma of another plant, leading to genetically different pollen grains.

Option C (40) is correct because each microspore mother cell produces 4 pollen grains after meiotic division. Therefore, ten microspore mother cells will produce 40 pollen grains.

Option D (Cleistogamy) is correct because Commelina often exhibits cleistogamy, where flowers do not open and self-pollination occurs within the closed flower.

Option D is correct because germ pores are present on the exine (outer wall) of the pollen grain, not the intine (inner wall).

Option A (Male gamete fuses with female gamete) is correct because syngamy is the fusion of the male and female gametes to form a zygote.

Option A (Haploid plant) is correct because a plant raised from a single germinating pollen grain is haploid, as pollen grains are haploid.

Option B (If both Assertion and Reason are true but Reason is not the correct explanation of Assertion) is correct because both statements are true, but parthenocarpy isn't the reason why ovaries form fruits after fertilization.

The correct answer is C (Both (a) and (b)) because both Castor and Coconut are known to have endospermic seeds, where the endosperm persists in the mature seed.

The correct answer is A (TRUE) because increasing the number of pollen grains enhances the chances of successful pollination in wind and water-pollinated plants due to the randomness of these processes.

Option A (Middle layer) is correct because the middle layer of the anther wall, consisting of 2-3 layers of cells, is ephemeral and degenerates during microspore maturation.

Option B (Banana) is correct because banana plants are monocarpic, meaning they flower once and then die.

Option C (Double fertilisation) is correct because endosperm formation is a direct result of the fusion of a sperm nucleus with the polar nuclei during double fertilization.

Option B (12) is correct because gametes are haploid, containing half the number of chromosomes as the diploid root cells.

Option D (Fragrance) is correct because nectar, safe place for egg laying, and pollen grains are direct rewards for the insect in entomophily, while fragrance is just an attractant.

Option D (Two polar nuclei) is correct because in angiosperms, triple fusion involves the fusion of a second sperm with two polar nuclei to form the endosperm.