Q61. The process of fusion of two morphologically similar gametes is called:
[A] Oogamy
[B] Anisogamy
[C] Isogamy
[D] Syngamy
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Correct Answer: [C] Isogamy
Explanation: Isogamy is a type of sexual reproduction that involves the fusion of two gametes that are morphologically similar in size and shape. These gametes may be flagellated and motile, or non-flagellated and non-motile.
Q62. The process of fusion of two gametes that are dissimilar in size is called:
[A] Isogamy
[B] Oogamy
[C] Anisogamy
[D] Fertilization
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Correct Answer: [C] Anisogamy
Explanation: Anisogamy (or heterogamy) is a type of sexual reproduction that involves the fusion of two gametes that differ in size. Typically, the female gamete is larger and less motile, while the male gamete is smaller and more motile.
Q63. The process of fusion of a large, non-motile female gamete with a smaller, motile male gamete is called:
[A] Anisogamy
[B] Isogamy
[C] Oogamy
[D] Syngamy
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Correct Answer: [C] Oogamy
Explanation: Oogamy is a type of sexual reproduction where the female gamete is large and non-motile (the egg or ovum), and the male gamete is smaller and motile (the sperm). This is the most common type of sexual reproduction in plants and animals.
Q64. Which of the following algae exhibits isogamous sexual reproduction?
[A] Volvox
[B] Fucus
[C] Spirogyra
[D] Chara
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Correct Answer: [C] Spirogyra
Explanation: Spirogyra, a green alga, typically exhibits isogamous sexual reproduction, where two morphologically similar, non-flagellated gametes fuse to form a zygote.
Q65. Which of the following algae exhibits oogamous sexual reproduction?
[A] Ulothrix
[B] Cladophora
[C] Volvox
[D] Ectocarpus
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Correct Answer: [C] Volvox
Explanation: Volvox, a green alga, exhibits oogamous sexual reproduction, where there is a large, non-motile female gamete (egg) and smaller, motile male gametes.
Q66. In gymnosperms, the reduction division occurs in the:
[A] Zygote
[B] Spores
[C] Gametes
[D] Sporangia
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Correct Answer: [D] Sporangia
Explanation: In gymnosperms, meiosis (reduction division) occurs in the sporangia (both microsporangia and megasporangi[A] to produce haploid spores. These spores then develop into the gametophytes.
Q67. The transfer of pollen grains from the anther to the stigma is called:
[A] Fertilization
[B] Syngamy
[C] Pollination
[D] Double fertilization
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Correct Answer: [C] Pollination
Explanation: Pollination is the process of transfer of pollen grains from the anther (male reproductive part) to the stigma (female reproductive part) of a flower. It is a crucial step in the sexual reproduction of angiosperms.
Q68. The fusion of male and female gametes is called:
[A] Pollination
[B] Fertilization
[C] Syngamy
[D] Both b and c
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Correct Answer: [D] Both b and c
Explanation: The fusion of a male gamete with a female gamete is called fertilization or syngamy. This process results in the formation of a diploid zygote.
Q69. Which of the following is a seedless vascular plant?
[A] Pinus
[B] Cycas
[C] Equisetum
[D] Gnetum
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Correct Answer: [C] Equisetum
Explanation: Equisetum (horsetail) is a pteridophyte, which is a vascular plant that reproduces via spores and does not produce seeds. Pinus, Cycas, and Gnetum are gymnosperms that produce seeds.
Q70. The vascular bundles in monocot stems are:
[A] Open and arranged in a ring
[B] Closed and scattered
[C] Open and scattered
[D] Closed and arranged in a ring
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Correct Answer: [B] Closed and scattered
Explanation: In monocot stems, the vascular bundles are closed (lacking cambium) and scattered throughout the ground tissue. This arrangement is different from that in dicot stems, where the vascular bundles are typically arranged in a ring and are often open.