Tiêu đề 24.Sexual Reproduction in Flowering Plants (AutoRecovered).pdf ✅

(c) each visit of pollinator brings hundreds of pollen grains. (d) seed set is not dependent upon pollinators. 22. Total number of meiotic division required for forming 100 zygotes /100 grains of wheat is (a) 100 (b) 75 (c) 125 (d) 50 23. Monoecious plant which prevents autogamy but not geitonogamy. NCERT Page-31 (a) castor (b) papaya (c) Maize (d) Both (a) and (c) 24. How many meiotic division are required for the formation of 100 functional megaspores? (a) 100 (b) 50 (c) 75 (d) 25 25. What is the main function of filiform apparatus present at the micropylar part of the ovule? (a) It prevents the entry of more than one pollen tube into the embryo sac. NCERT Page-33, 27/N − 11 (b) It helps in the entry of pollen tube into an antipodal cell. (c) It helps the pollen tube to enter the ovule through chalazal end. (d) It guides the entry of pollen tube into a synergid and discharge the male gametes. 26. Germ pore / germinal furrow present on the surface of pollen grain represents (a) area where exine is thin or absent. (b) specialised thickening of exine. (c) specialised thickening of intine. (d) area where tapetum is absent. 27. Self-pollination means NCERT Page-27 / N-12 (a) transfer of pollen from anther to stigma in the same flower. (b) transfer of pollen from one flower to another on the different plant. (c) occurence of male and female sex organ in the same flowers. (d) germination of pollen. 28. The function of anther is NCERT Page-21 / N-5 (a) produce a cellular structure of sporo- pollenin. (b) produce pollen grains. (c) store and protect pollen grains. (d) All the above 29. Cross pollination produces (a) similar offspring (b) weaker progeny (c) better progeny (d) male progeny 30. Pollen grains are preserved as fossils because of the NCERT Page-23 / N-7 (a) Presence of cellulose & pectin (b) Presence of sporopollenin (c) Presence of lignin (d) Presence of cellulose 31. Intine of pollen grain is made of NCERT Page-23 / N-7 (a) callose (b) pecto-cellulose (c) cellulose (d) sporopollenin 32. The structure of bilobed anther consists of NCERT Page-21 / N-5 (a) 2 thecae, 2 sporangia (b) 4 thecae, 4 sporangia (c) 4 thecae, 2 sporangia (d) 2 thecae, 4 sporangia 33. Pollen grains are well preserved as fossils because of presence ofNCERT Page-23 / N-7 (a) sporopollenin (b) cellulose (c) lignocellulose (d) pectocellulose 34. ____of the pollen grain divides to form two male gametes. NCERT Page-23 / N-7 (a) Vegetative cell (b) Generative cell (c) Microspore mother cell (d) None of these
35. Which of the following statement is incorrect about emasculation?NCERT Page-33/N-17 (a) During emasculation process, stigma is removed. (b) Emasculated flowers are bagged in order to prevent self-pollination. (c) Emasculation is an outbreeding device to promote cross-pollination.. (d) It is one of the steps for artificial hybridization. 36. The given figure represent the L.S of a flower showing growth of pollen tube. Few structures are marked as A, B, C,D & E. Identify A, B, C,D and E respectively. NCERT Page-32/N-16 (a) Antipodal cells, Polar nuclei, Stigma, Style, Chalaza (b) Antipodal cells, Polar nuclei, Style, Stigma, Chalaza (c) Antipodal cells, Polar nuclei, Stigma, Chalaza, Style (d) Antipodal cells, Polar nuclei, Chalaza, Stigma, Style 37. In the figure of anatropous ovule given below, choose the correct option for the characteristic distribution of cells within the typical embryo sac NCERT Page-25 & 26 / N − 19 Number of cells at chalazal end Number of cells at micropylar end Number of nuclei left in central cell (a) 3 2 3 (b) 3 3 2 (c) 2 3 3 (d) 2 2 4 38. Sequence of development during the formation of embryo sac is NCERT Page-26 / N-10 (a) Megaspore → Megaspore mother cell → Embryo sac. (b) Megasporocyte → Megaspore → Embryo sac. (c) Megaspore → Megaspore mother cell → Embryo sac. (d) Megaspore mother cell → Megaspore → Embryo sac. 39. Which of the following processes is necessary for the complete development of male gametophyte? (a) One meiotic cell division and two mitotic cell divisions. NCERT Page-21 & 22/ N-6 (b) One meiotic cell division and one mitotic cell division. (c) Two meiotic cell divisions and one mitotic cell division. (d) Two mitotic cell divisions. 2.3 DOUBLE FERTILISATION 40. In a fertilized ovule, n, 2n and 3n conditions occur respectively in NCERT Page-18 (a) antipodal, egg and endosperm. (b) egg, nucellus and endosperm. (c) endosperm, nucellus and egg. (d) antipodals, synergids and integuments.