CDS 1 2021 General Knowledge Question Paper with Answer Key

Ans. A.

• Pinaka is an indigenous MBRL (Multi-Barrel Rocket Launch) system developed by DRDO for the Indian Army. It is one of the most reliable and effective weapon systems of the Indian Army.
• Whole Pinaka MBRL has six launcher vehicles, each comprising 12 rockets with six loader-replenishment vehicles & two command post vehicles with DIGICORA MET radar and a fire control computer.
• It was used in the year 1999 Kargil war in which it proved its worth.

Ans. D.

• Osmosis can be defined as the spontaneous movement of solvent molecules from a region of high solvent potential to a region of lower solvent potential through a partially semi-permeable membrane. This is a process that can be used to purify water.

Ans. B.

• Mitochondria, and plastids contain their own DNA and ribosomes because of that they are able to synthesize some of their own proteins and replicate independently of the nucleus. This genetic material is also called mtDNA or mitochondrial DNA.

Ans. C.

• Cytokinins are essential to plant hormones that influence growth, and the stimulation of cell division. Cytokinins are known to regulate axillary bud growth and apical dominance. They help in the production of new leaves, chloroplasts, and adventitious shoots.

Ans. B.

• In the self-pollination process, the pollen grains transfer from the stigma of the same or genetically similar flower. A flower is self-pollinated if pollen is transferred to it from any flower of the same plant. Genes are not diverse in nature, therefore, the purity of the race is maintained. The plants do not depend on external factors for pollination.

Ans. D.

• Cell wall is made up of cellulose, and they are present in most prokaryotes (except mollicute bacteria), in fungi, algae, and eukaryotes including plants cell. Cell walls are absent in animals. Humans have skeleton support and cell walls function is to provide skeletal support

Ans. D.

• Cardiac muscles (the heart muscle) are branched and cylindrical in shape. They are uninucleated cells, and they are under involuntary control. The cardiac muscle performs coordinated contractions which allowed the heart to pump blood through the circulatory system.

Ans D

• Planarians are free-living flatworms, they are not directly dependent on another organism for survival. They inhabit freshwater, and they are carnivorous (even they don’t have teeth) or scavengers.

Ans. A.

• African trypanosomiasis is also known as sleeping sickness. It is due to microscopic parasites of the Trypanosoma brucei species, transmitted through the tsetse fly. That is found only in sub-Saharan Africa

Ans. D.

• Viruses are different from bacteria, they have a different structure and a different way of surviving. They also don’t have cell walls that can be attacked by antibiotics, instead, viruses are surrounded by a protective protein coat. Viruses actually digress into, live in, and make new copies of themselves within a host cell. They can’t reproduce on their own, as bacteria do, Instead, they attach themselves to healthy cells and reprogram those cells to make new viruses. It is because of these reasons antibiotics are not effective on viruses.

Ans. B.

• Aluminum is manufactured through two phases- the Bayer process and the Hall-Heroult process. Aluminum originates from bauxite ore to obtain aluminum oxide. By refining and smelting, the aluminum oxide then releases pure aluminum. A white powder from which aluminum can be extracted. The extraction is done by electrolysis. During electrolysispositively charged aluminum ions gain electrons and form molten aluminum from the cathode, and oxide ions lose electrons and form oxygen molecules at the anode.

• Ans. C.

Ans. B.

• Sodium is kept immersed in Kerosene oil to protect it and to prevent accidental fire. Sodium is a highly reactive metal. It vigorously reacts with the oxygen, carbon dioxide, and moisture present in the air that causes a fire. For preventing this explosive reaction, Sodium is kept immersed in kerosene because it does not react in kerosene oil. Like sodium, potassium is also a highly reactive metal.

Ans. A.

• The silver article becomes black after reacts with sulfur which is present in the atmosphere. Then sulfur forms silver sulfide on the surface of the silver article, so they appear as dull or black. This layer of silver sulfide can be removed by rubbing the article with toothpaste because toothpaste consists of several abrasive substances like Aluminum hydroxide that makes silver metal all shiny.

Ans. D.

When we heat lead nitrate [pb(NO3)2 ] in a boiling tube, we observe the emission of brown fumes of NO₂ . It is a thermal decomposition reaction. When [pb(NO3)2 is broken down into lead oxide, nitrogen dioxide, and oxygen. In this decomposition reaction, Lead Nitrate gives a yellowcolored Lead oxide, and Nitrogen dioxide is released as brown fumes

Ans. D.

This slaked lime reacts with in the air to form a thin layer of to give a shiny finish. The calcium oxide (CaO) is also called quicklime. It is used for whitewashing by producing calcium hydroxide (CaOH). Calcium hydroxide reacts with water and absorbs carbon dioxide ( CO₂) from the environment. Then it produces calcium carbonate (CaCO₃ ) which creates a shiny finish on the walls.

Ans. A.

• Hard water can be softened by washing soda or sodium carbonate . It removes the calcium ions in a precipitation reaction from the hard water. And then the hard water passed through an ion-exchange resin in a column. In the water, sodium ions replace the calcium ions when it passes through the column.
• Water is categorized into two types. They are hard, and soft water.
• Hard water- water with naturally present minerals like magnesium and calcium. These are beneficial for health.
• Soft water- it is left with only cations, and that is sodium. It has a salty taste. Do not leave any spots on dishes after wash. Soap is easily effective.

Ans. B.

• The formula of soda acid is NaHCO3. The soda acid fire extinguisher contains sodium bicarbonate and sulfuric acid. It is the most effective household fire extinguisher. Sulfuric acid is kept inside the iron vessel. Any fire extinguisher is a cooling of the combustible material, cut off the air supply. Soda acid fire extinguisher acts on all fire except due to electrical and inflammable liquid.

Ans. B.

• Citric acid naturally occurring acids is found in abundance in tomato. Acids are in sour and turn blue litmus paper into red color.
• Acids are corrosive, and also gives carbon dioxide gas after reacting with metal carbonates and bicarbonates.
• Citric acid- a natural source of this acid is found in sour substances like lemon, orange, tomatoes, etc.
• Formic acid- is naturally found in red ant sting.
• Tartaric acid- found in many fruits, grapes, bananas, tamarinds, etc.
• Oxalic acid- naturally found in spinach, etc.

Ans. C.

• Fission is related to the creation of new individuals through cell division in the unicellular organism of the living cell. In nuclear fission, it is related to the transformation of heavier nuclei into smaller nuclei. Nuclear fission in an atom splits into two or smaller atoms, as a result of neutron bombardment. It is an exothermic reaction. Most fission are binary fission. And they produce two charged fragments.