Question Discussion & Solution

The correct answer is Fermentation.

Key Points

• Fermentation:
  • The biological process, in which sugar molecules are converted into ethyl alcohol and carbon dioxide with the help of some microbes like yeast and bacteria is called alcohol fermentation.
  • It is an anaerobic process. i.e. it occurs in the absence of oxygen.
  • The process is governed by the enzyme alcohol dehydrogenase
  • Alcoholic fermentation has many uses such as for the production of alcoholic beverages, ethanol fuel, and bread cooking.

Additional Information

• Moulding:
  • ​Moulding is a typical process in which a type of fungus that grows surface of fruits and vegetable.
  • These tubular branches have multiple, genetically identical nuclei, yet form a single organism, known as a colony.
  • In contrast, yeast is a type of fungus that grows as a single cell.
• Nitrogen Fixation:
  • Nitrogen fixation is the chemical process by which atmospheric nitrogen is assimilated into organic compounds, especially by certain microorganisms as part of the nitrogen cycle. 
  • Atmospheric nitrogen is fixed by several methods like biological N2 fixation, Industrial N2 fixation & Electrical N2 fixation.
  • It is a necessary process, as the fixed nitrogen is used in the biosynthesis of several organic compounds like amino acids, proteins, nucleic acids, etc.
• Transcription:
  • ​The process of copying genetic information from one strand of DNA into RNA is termed transcription or mRNA synthesis.
  • The process of transcription begins when an enzyme called RNA polymerase attaches to the template DNA strand and begins to catalyze the production of complementary RNA.
  • It is completed in three steps Initiation, Elongation & Termination.

The correct answer is Red.

Key Points

• Sulphuric acid is also known as oil of vitriol.
• It is composed of sulfur, hydrogen, and oxygen element.
• The acid has a very strong acidic nature.
• It has several uses such as fertilizer manufacture, mineral processing, oil refining, and wastewater processing.
• It is also known by the name hydrogen sulfate.

Important Points 

• The litmus solution is a purple dye solution.
• It is extracted from the plant called " Lichen".
• It is used as an acid-base indicator.

The correct answer is Open Cast Mining.

• Open Cast Mining is the process under which minerals are mined near the earth's surface.

Key Points

• Opencast mining is the process that involves the removal of ore from seams relatively near the surface by means of an open-pit.
• These mines occupy a large area of land for excavation of the ore and disposal of the overburden.

Additional Information

• Drilling is a cutting process which uses a drill bit to cut a hole of circular cross-section in solid materials or ground.
• Quarrying is the process of removing rock, sand, gravel or minerals from the ground in order to use them to produce materials for construction or other uses.
• Shaft mining is the process where miners dig straight down until they reach their desired depth. 

The correct answer is Curvature of the lens.

Important Points

• Focal length of a lens depends on its curvature and the medium outside the lens.

Additional Information

• The ability of a lens to converge or diverge light rays depends on its focal length.
  • For example, a convex lens of short focal length bends the light rays through large angles, by focussing them closer to the optical centre.
  • Similarly, the concave lens of a very short focal length causes a higher divergence than the one with a longer focal length.
• The degree of convergence or divergence of light rays achieved by a lens is expressed in terms of its power.
  • The power of a lens is defined as the reciprocal of its focal length.

The correct answer is Virus protection.

Functions of operating system are:

• Therefore, Virus Protection is not the function of OS. It is a function of Firewall and Antivirus.