Optionals IAS Mains Botany: Questions 67 - 74 of 511

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Question 67

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Appeared in Year: 2014 (IFS)

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Essay▾

What are the angiospermic features of Gnetum? (Paper - 1, Section - B)

Explanation

Angiospermic Features of Gnetum

  • Gymnosperms have naked-seeds but not fruits or flowers.
  • Gymnosperms developed during the Paleozoic Era and became dominant during the early Mesozoic Era.
  • The presence of companion cells in the angiosperms is one of the constant anatomical features which distinguish gymnosperm with the angiosperm.
  • Gnetum belongs to gymnos…

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Question 68

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Appeared in Year: 2014 (IFS)

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Essay▾

Write the botanical name, family, active constituents and uses of any five medicinal plants of commercial importance in India. (Paper - 1, Section - B)

Explanation

Turmeric (Haldi)

Botanical name: Curcuma longa

Family: Zingiberaceae

Active constituent:

Curcumin (diferuloylmethane) is a polyphenol compound responsible for the bright yellow color of turmeric.

Uses

  • Use as the blood purifier and is very useful in the common cold, leprosy, affections of the liver, dropsy and wound healing.
  • Used in the cosmetics.
  • Sweetened…

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Question 69

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Appeared in Year: 2014 (IFS)

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Explain the following in about 150 words each: Ribosomes are synthesized? (Paper 2 - Section A)

Explanation

Synthesised Ribosomes

  • Ribosome is a complex of ribosomal ribonucleic acid (rRNA) and protein.
  • The rRNA part is synthesized from the original message called DNA in the nucleus, particularly in a region called nucleolus.
  • Molecules of rRNA are synthesized in a specialized region of the cell nucleus called the nucleolus, which appears as a dense area with…

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Question 70

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Appeared in Year: 2014 (IFS)

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Describe the differences and importance of afforestation, reforestation and social forestry. (Paper 2, Section B)

Explanation

Differences Among Afforestation, Reforestation and Social Forestry

  • Afforestation is the process of establishing forests in areas that have never been forested while reforestation is the restoration of forests in areas where forests were removed or destroyed.
  • Both afforestation and reforestation are the converse of avoiding deforestation.
  • While Social …

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Question 71

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Appeared in Year: 2014 (IFS)

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Essay▾

Write brief notes on the following in about 150 words each: Eutrophication

(Paper 2, Section B)

Explanation

Eutrophication

  • Eutrophication is the over-enrichment of water by nutrients (e. g. from chemical fertilizer or sewage) which is causing overgrowth and decay of plants, deoxygenation of water, and the death of its organisms.
  • This enhanced plant growth, often called an algal bloom, reduces dissolved oxygen in the water when dead plant material decompose…

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Question 72

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Appeared in Year: 2014 (IFS)

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Write brief notes on the following in about 150 words each: Fermentation (Paper 2, Section B)

Explanation

Fermentation

  • Fermentation is a natural process. People applied fermentation to make products such as wine, mead, cheese and beer long before the biochemical process was understood.
  • In the 1850s and 1860s Louis Pasteur became the first scientist to study fermentation when he demonstrated fermentation was caused by living cells.
  • He also recognized that …

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Question 73

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Appeared in Year: 2014 (IFS)

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What is accounted for by Lyon՚s hypothesis? Cite an example. (Paper 2 - Section A)

Explanation

The Lyon՚S Hypothesis

  • The Lyon՚s hypothesis was described by Mary Lyon in 1962.
  • The Lyon՚s hypothesis does not related to germ cells and explains the phenomenon of heterozygous female carries of X-lined recessive disorders showing features of the condition.
  • The Lyon՚s hypothesis was also explains the phenomenon of Barr bodies.
  • The Lyon hypothesis relat…

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Question 74

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Appeared in Year: 2014 (IFS)

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Write brief notes on the following in about 150 words each: Endemism (Paper 2, Section B)

Explanation

Endemism

  • Endemism means the situation in which a species is restricted to a particular geographic region as a result of factors such as isolation or in response to abiotic conditions.
  • Endemic species is only found in a given region or location and nowhere else in the world. If they are extinct in their endemic ecosystem, they are lost forever.
  • The eco…

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