Question Discussion & Solution

The correct answer is Hexadecimal.

Key Points

• The hexadecimal Number system Contains 16 digits.
• The base of this number system is 16.
• It comprises 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F.

Additional Information

• About Binary number system:
  • There are only 2 digits in the Binary system, which are 0 and 1.
  • The base of this number system is 2.
  • This number system is used by all digital computers to convert the data input from decimal to its binary equivalent.
• About Decimal number system:
  • It contains 10 digits.
  • It comprises 0,1,2,3,4,5,6,7,8,9.
  • The base of this number is 10.
• About Octal number system:
  • It contains 8 digits.
  • The base of this number is 8.

The correct answer is Aravali.

• Aravali range forms the main water area for Rajasthan.

Key Points

• Aravali range​
  • The Aravallis of Northwestern India, one of the oldest fold mountains of the world, now form residual mountains with an elevation of 300m. to 900m.
  • They stretch for a distance of 800 km from Himmatnagar in Gujarat to Delhi, spanning Haryana, Rajasthan, Gujarat, and Delhi, the 692 kilometres (km).
  • The Aravallis act as a barrier between the fertile plains in the east and the sandy desert in the west.
  • Historically, it is said that the Aravalli range checked the spread of the Thar desert towards the Indo-Gangetic plains, serving as a catchment of rivers and plains.
  • Thus Aravali range forms the main water area for Rajasthan.

​Additional Information

•  Aravali range formation
  • ​These are fold mountains of which rocks are formed primarily of the folded crust when two convergent plates move towards each other by the process called orogenic movement.
  • The Aravallis date back to millions of years when a pre-Indian sub-continent collided with the mainland Eurasian Plate.
  • Carbon dating has shown that copper and other metals mined in the ranges date back to at least the 5th century BC.

The correct answer is Leeuwenhoek.

Key Points

Additional Information

• Penicillin:
  • Penicillin is one of the first and still one of the most widely used antibiotic agents, derived from the Penicillium mold.
  • In 1928 Scottish bacteriologist Alexander Fleming first observed that colonies of the bacterium Staphylococcus aureus failed to grow in those areas of a culture that had been accidentally contaminated by the green mold Penicillium notatum.
  • He isolated the mold, grew it in a fluid medium, and found that it produced a substance capable of killing many of the common bacteria that infect humans.
  • Australian pathologist Howard Florey and British biochemist Ernst Boris Chain isolated and purified penicillin in the late 1930s, and by 1941 an injectable form of the drug was available for therapeutic use.
• Microscope:
  • Microscope is an instrument that produces enlarged images of small objects, allowing the observer an exceedingly close view of minute structures at a scale convenient for examination and analysis.
  • Although optical microscopes are the subject of this article, an image may also be enlarged by many other waveforms, including acoustic, X-ray, or electron beam, and be received by direct or digital imaging or by a combination of these methods.
  • The microscope may provide a dynamic image (as with conventional optical instruments) or one that is static (as with conventional scanning electron microscopes).
• Reverse transcriptase:
  • Reverse transcriptase also called RNA-directed DNA polymerase, an enzyme encoded from the genetic material of retroviruses that catalyzes the transcription of retrovirus RNA (ribonucleic acid) into DNA (deoxyribonucleic acid).
  • This catalyzed transcription is the reverse process of normal cellular transcription of DNA into RNA, hence the names reverse transcriptase and retrovirus.
  • Reverse transcriptase is central to the infectious nature of retroviruses, several of which cause disease in humans, including human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS), and human T-cell lymphotropic virus I (HTLV-I), which causes leukemia.
• Bacteria:
  • Bacteria, singular bacterium, any of a group of microscopic single-celled organisms that live in enormous numbers in almost every environment on Earth, from deep-sea vents to deep below Earth’s surface to the digestive tracts of humans.
  • Bacteria lack a membrane-bound nucleus and other internal structures and are therefore ranked among the unicellular life-forms called prokaryotes.
  • Prokaryotes are the dominant living creatures on Earth, having been present for perhaps three-quarters of Earth history and having adapted to almost all available ecological habitats.
  • As a group, they display exceedingly diverse metabolic capabilities and can use almost any organic compound, and some inorganic compounds, as a food source.

Explanation:

Trend in metallic property:

• As we move along a period from left to right, the metallic character decreases. The elements which are at the extreme left of the periodic table are most metallic in nature and the elements at the right side of the periodic table are non-metals in nature.
• As we go down the group, the metallic character increases and the non-metallic character decreases.
• So, metals at the extreme left and bottom of the periodic table are most metallic in nature.

Reactivity:

• As the metallic character increases, the Ionisation potential decreases and the reactivity of the elements also increases.
• The most reactive metal is thus Cs (Cesium), situated at the bottom left corner of the periodic table.

​

Hence, the most active metal known is Cesium.

• Francium is the element present at the bottom of the periodic table, but it is a lab-made element, and not naturally occurring, which makes Cs as the most reactive element. 

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.