NEET UG Biology Sexual Reproduction in Flowering Plants MCQs

IMPORTANT POINTS

- Reproduction is the most important feature of living organisms.

- It is a process of producing offspring, ie., the next generation, which is a means of self-perpetuation.

- In sexual reproduction, fusion of male and female gametes takes place.

- Flowers are reproductive organs of plants.

- A typical flower has four whorls – From the outer side

- stamens are actually microsporophylls. It is a male reproductive part.

It has three parts

   (1) Anther

   (2) connective and

   (3) Filament.

- Anther is bilobed structure having four microsporangia.

- It’s wall has four layers (i) Epidermis (ii) Endothecium (iii) middle layers and (iv) Tapetum.

- Microsporangium at the centre possesses sporogenous tissue.

- The sporogenous tissue by meiotic division produces large number of microspore tetrads.

- Each microspore matures to form pollen grain.

- Pollen wall is two layered. (i) Exine – outer hand layer (ii) Intine – Inner thin layer.

- Exine has prominent apertures called Germpores, at which place sporopollenin is absent.

- Intine develops as a pollen tube and comes out of germ pores.

- During further development of male gametophyte, the pollen nucleus divides to form (1) vegetative cell / nucleus and (2) Generative cell / nucleus. Vegetative nucleus disintegrater later on and the generative nucleus divides to produces two male gametes.

- A Gynoecium (pistil) is like megasporophyll.

- It is female reproductive part.

- It has three region (i) Stigma (ii) Style (iii) Ovary.

- Ovule (megasprangium) is developed from the placenta inside the ovarium cavity.

- The stalk of the ovule is called funicle. Ovule is covered by one or two integuments; leaving a small opening called micropyle.

- Only one megaspore mother cell located towards micropylar divides meiotically to form four haploid megaspore arranged linearly called linear tetrad.

- Of the four only one becomes functional. It forms female gametophyte (Embryo sac)

- The mature embryo sac is 7 celled; but 8 nucleated.

- Here 3 nuclei get organized into an egg-apparatus, which consist of 1 egg cell and two synergids, toward micropylar end.

- While towards challazal end, three nuclei get organized to form antipodal cells.

- From each end one nuclei each comes in the middle, untie to form one cell, called secondary nucleus, which has two nuclei.

- Pollination -

- The process of transfer of pollen grain from the anther to the stigma is called pollination.

- Pollination are of two types (1) self and (2) cross.

- Self-pollination can occur in bisexual as well as unisexual flowers while cross pollination is possible only in unisexual flowers naturally.

- Homogamy and cleistogamy are the adaptations for self-pollination while Dichogamy is for selfsterility.

- Hetrostyled is for cross pollination.

- Different pollinating agents are

   (a) Abiotic - (i) wind and (ii) water.

   (b) Biotic animals like , Insects, birds etc.

- pollen – pistil interaction involves all events from landing of pollen grains to the stigma until the pollen tube enters the embryo sac. 

M.C.Q.

57. Two male gametes are

(a) produced before pollination (b) Haploid

(c) Diploid (d) At the time of pollination

 

58. The innermost layer of the wall of microsporangium is called

(a) Endothecium (b) Endodermis (c) Tapetum (d) Intine

 

59. Pollen grains represent

(a) The future sporophyte (b) The sporophyte

(c) The gametophyte (d) The male gametophyte

 

60. Tapetum provides

(a) protection to embryo (b) Nourishment to pollen grains

(c) Nourishment to embryo (d) Protection to endosperm

 

61. In triple fusion, how many male gamete participate ?

(a) 1 (b) 2 (c) 3 (d) 4

 

62. Germpores are actually

(a) Apertures in intine (b) Thick area in intine

(c) Apertures in exine (d) Thin area in intine

 

63. Radicle tip is derived from

(a) Suspensor (b) Proembryo (c) Basal cell (d) Hypophysis

 

64. How many haploid nuclei are involved in double fertilization ?

(a) Four (b) Two (c) Five (d) Three

 

65. Endothecium in anther helps in

(a) Dehiscence of anther (b) Nutrition to pollen

(c) Germination of pollen (d) Formation of male gamete

 

66. The intine of a pollen grain is made up of

(a) Lignin and suberin (b) Pectin and cellulose

(c) Lignin and Hemicellulose (d) Pectin and callose

 

67. Which is the most resistant natural organic material ?

(a) Cellulose (b) Pectin (c) Suberin (d) Sporopollenin

 

68. Style is

(a) a is delicate hollow tube (b) a tough hollow tube

(c) a delicate filament (d) called pollen tube

 

69. Nucellus is mass of

(a) Parenchymatous tisse (b) Sclerenchymatous tissue

(c) Meristematic tissue (d) Collenchymatous tissue

 

70. Which one of the following is the example of mitosis ?

(a) Megasporongensis (b) Microsporogensis

(c) Pollen formation (d) Division of generative cell

 

71. Typical anther normally consists of

(a) One lobe Four sporangia (b) Two lobe Two sporangia

(c) Two lobe Four sporangia (d) One lobe Two sporangia

 

72. During the development of monosporic development of embryo sac the nucleus of the functional megaspore divides

(a) Two times (b) Three times (c) One time (d) Repeatedly

 

73. Cross pollination has an advantage of

(a) Mutation(b) polyploidy formation (c) Genetic recombination (d) Crossing over

 

74. Unisexual flowers prevent

(a) Pollination (b) Breeding (c) Self-pollination (d) Cross fertilization

 

75. The functionof the filiform apparatus is

(a) To nourish the pollen grain (b) To guide the entry of pollen tube

(c) To develop pollen tube (d) To carry pollen tube through style

 

76. Which one of the following is an example of free-nuclear endosperm

(a) Coconut water (b) Castor (c) Sugarcane juice (d) Groundnut

 

77. The protective cover of the radicle in maize seed is called

(a) Micorhiza (b) Coleptile (c) Scutelum (d) Coleorhiza

 

78. In angiosperm the endosperm is formed

(a) In the nucellus (b) In the embryo sac (c) In the seed (d) In the anther

 

79. Stamen show homology with

(a) Gametophyte (b) male cone (c) Microsporophyll (d) Sporangium

 

80. The pedicel of the female flower coils after pollination in

(a) Lotus (b) Hydrilla (c) Vallisneria (d) Trapa

 

81. The arrangement of the ρ haploid nuclei in the normal dicot embryo sac is

(a) 2 + 3 + 3 (b) 2 + 3 + 2 (c) 3 + 3 + 2 (d) 3 + 2 + 3

 

82. In the flowering plants, male and female gametes both are

(a) Motile (b) Non-motile (c) Diploid (d) Very large

 

83. Wind pollination requires that the pollen grains are

(a) Heavy and wet (b) Heavy and non-sticky (c) Light and dry (d) Heavy and sticky

 

84. Future sporophytic generation in a seed is

(a) Cotyledon (b) Endosperm (c) Hypocotyl (d) Embryo

 

85. Scatelum is

(a) an endosperm (b) a seed coat (c) an embryo (d) a cotyledon

 

86. Which one of the following floats in the cytoplasm of the vegetative cell ?

(a) Male gamete (b) Generatic cell (c) Female gamete (d) Microspore

 

87. The mature pollen grain contains

(a) 3 cells (b) 7 cells (c) 2 cells (d) 1 cell

 

88. Pollen tube is formed by

(a) Germ pore (b) Exine (c) Style (d) Intine

 

89. A single ovule produces

(a) 3 female gamete (b) 1 female gamete(c) 2 female gamete (d) 4 female gamete

 

90. Embryo sac is formed inside

(a) Seed (b) Endosperm (c) Embryo (d) Ovule

 

91. Pro-embryo is a

(a) 8 celled structure (b) 4 celled structure

(c) 2 celled structure (d) 16 celled structure

 

92. Suspensor is made up of

(a) 2 to 4 cells (b) 4 to 8 cells (c) 8 to 16 cells (d) 20 to 25 cells

 

93. Root cap of the embryo develops from

(a) Basal cell (b) Apical cell (c) Hypophysis (d) Hypocotyl

 

94. The hilum of the ovule represents the junction between

(a) Nucellus and Embryo (b) Nucellus and Integuments

(c) Funicle and Integuments (d) Funicle and ovule

 

95. Which layer of the wall of microsporangium is made up of Fibrous layer

(a) Middle layer (b) Endothecium (c) Tapetum (d) Epidermis

 

96. Out of the four sets of appendages of a typical flower the outer two sets are

(a) Fertile (b) Reproductive (c) Sterile (d) Filamentous

 

97. A proximal sterile part of the stamen is called

(a) Style (b) Connective (c) Anther (d) Filament

 

98. A sterile region present between stigma and ovary is called

(a) Pollen tube (b) Style (c) Filament (d) Suspensor

 

99. The opposite end of the micropylar region of an ovule is called

(a) Embryo sac (b) Nucellus (c) Chalaza (d) Thalamus

 

100. When pollen grains are not transferred from anthers to stigma in a flower, due to the physical barrier,it is called

(a) Cleistogamy (b) Herkogamy (c) Dichogamy (d) Heterogamy

 

101. The asexual production of seed is called

(a) Fragmentation (b) Apomixis (c) Self-fertilization (d) Dormancy

 

102. Perisperm is

(a) Peripheral part of endosperm (b) Remnent of endosperm

(c) Disintegrated secondary nucleus (d) persistant of nucleus

 

103. The root cell of wheat plant has 42 chromosomes. What would be the number of chromosomes in the synergid cell ?

(a) 21 (b) 7 (c) 28 (d) 14

 

 

104. The plant part which consist of two generations, one within the other, is

(a) Germinated pollen grain (b) Embryo

(c) Unfertilized ovule (d) Seed

 

105. The pollen tube usually enters the female gametophyte

(a) through one of the synergids (b) by directly penetrating the egg

(c) between one synergid and central cell (d) by knocking off the antipodal cell