Q71. The vascular bundles in dicot stems are typically:
[A] Closed and scattered
[B] Open and arranged in a ring
[C] Closed and arranged in a ring
[D] Open and scattered
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Correct Answer: [B] Open and arranged in a ring
Explanation: In dicot stems, the vascular bundles are typically open (containing cambium) and arranged in a ring surrounding the pith. This arrangement allows for secondary growth in dicots.
Q72. Which of the following is a source of medicine?
[A] Spirogyra
[B] Pinus
[C] Funaria
[D] Ephedra
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Correct Answer: [D] Ephedra
Explanation: Ephedra is a gymnosperm that has been used for medicinal purposes for centuries. It is a source of ephedrine, a stimulant and decongestant.
Q73. Which of the following is used as a biofertilizer?
[A] Chlorella
[B] Anabaena
[C] Sargassum
[D] Dictyota
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Correct Answer: [B] Anabaena
Explanation: Anabaena is a cyanobacterium (blue-green alg[A] that can fix atmospheric nitrogen. It is used as a biofertilizer, especially in paddy fields, to enhance soil fertility.
Q74. The process of fusion of the male gamete with the egg cell is called:
[A] Triple fusion
[B] Vegetative fertilization
[C] Generative fertilization
[D] Syngamy
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Correct Answer: [D] Syngamy
Explanation: Syngamy is the fusion of the male gamete with the egg cell to form the diploid zygote. This is one of the two fertilization events that occur in the double fertilization of angiosperms.
Q75. The process of fusion of the second male gamete with the central cell in angiosperms is called:
[A] Syngamy
[B] Double fertilization
[C] Triple fusion
[D] Vegetative fertilization
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Correct Answer: [C] Triple fusion
Explanation: Triple fusion is the fusion of the second male gamete with the diploid secondary nucleus (formed by the fusion of two polar nuclei) in the central cell of the angiosperm embryo sac. This results in the formation of the triploid primary endosperm nucleus.
Q76. The outermost whorl of a flower is called the:
[A] Corolla
[B] Calyx
[C] Androecium
[D] Gynoecium
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Correct Answer: [B] Calyx
Explanation: The calyx is the outermost whorl of a flower and is usually composed of sepals, which are typically green and leaf-like and protect the flower bud.
Q77. The whorl of petals in a flower is called the:
[A] Calyx
[B] Corolla
[C] Androecium
[D] Gynoecium
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Correct Answer: [B] Corolla
Explanation: The corolla is the whorl of petals in a flower. Petals are often brightly colored to attract pollinators.
Q78. The male reproductive whorl of a flower is called the:
[A] Calyx
[B] Corolla
[C] Androecium
[D] Gynoecium
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Correct Answer: [C] Androecium
Explanation: The androecium is the male reproductive whorl of a flower and consists of stamens, each typically composed of an anther and a filament.
Q79. The female reproductive whorl of a flower is called the:
[A] Calyx
[B] Corolla
[C] Androecium
[D] Gynoecium
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Correct Answer: [D] Gynoecium
Explanation: The gynoecium is the female reproductive whorl of a flower and is composed of one or more carpels (pistils), each consisting of a stigma, style, and ovary.
Q80. A plant that produces spores is called a:
[A] Gametophyte
[B] Sporophyte
[C] Thallus
[D] Protonema
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Correct Answer: [B] Sporophyte
Explanation: A sporophyte is the diploid generation in the life cycle of plants that produces spores through meiosis. These spores then develop into the haploid gametophyte generation.