SSC CGL Previous Year Questions: General Science - 14 - SSC CGL MCQ

A cellulosic wall is found in the cells of plants.Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth.

The filtration unit of kidney is known as nephron. Kidneys filter the nitrogenous waste products of the body through nephron and throw them out in the form of urine. Kidneys and skin are the chief organs of excretion.

The nutritive tissue in the seeds of higher plants is known as endosperm. Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein.

Yeast is an important source of vitamin B. Yeasts are eukaryotic microorganisms classified in the kingdom Fungi, with 1,500 species (estimated to be 1% of all fungal species). Yeasts are unicellular, although some species with yeast forms may become multicellular through the formation of strings of connected budding cells known as pseudohyphae, or false hyphae, as seen in most molds.

Enzymes are proteins. Enzymes are large biological molecules responsible for the thousands of metabolic processes that sustain life. They are highly selective catalysts, greatly accelerating both the rate and specificity of metabolic reactions, from the digestion of food to the synthesis of DNA. Most enzymes are proteins, although some catalytic RNA molecules have been identified

Heating of ore below its melting point in the absence of air is known as calcinations. Calcinations is a thermal treatment process in presence of air or oxygen applied to ores and other solid materials to bring about a thermal decomposition, phase transition, or removal of a volatile fraction

The most electronegative element among the following is fluorine. Fluorine is a chemical element with symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.

NH₄Cl is the compound which possesses ionic, covalent and coordinate bonds. Ammonium chloride, an inorganic compound with the formula NH₄Cl, is a white crystalline salt, highly soluble in water. Solutions of ammonium chloride are mildly acidic. Sal ammoniac is a name of the natural, mineralogical form of ammonium chloride

The depletion of Ozone layer is mainly due to chlorofluorocarbons. A chlorofluorocarbon is an organic compound that contains only carbon, chlorine, and fluorine, produced as a volatile derivative of methane, ethane, and propane. They are also commonly known by the DuPont brand name Freons.

Bacterium is associated with tuberculosis, Fungus with ringworm, Protozoan with kala-azar and virus with influenza.

Matter waves are de Broglie waves. In quantum mechanics, the concept of matter waves or de Broglie waves reflects the wave-particle duality of matter. The theory was proposed by Louis de Broglie in 1924 in his PhD thesis. The de Broglie relations show that the wavelength is inversely proportional to the momentum of a particle and is also called de Broglie wavelength.

When the milk is churned vigorously, the cream is separated out due to centrifugal force. Centrifugal force is the apparent force that draws a rotating body away from the center of rotation. It is caused by the inertia of the body as the body's path is continually redirected.

Gas thermometers are more sensitive than liquid thermometers because the gases have large coefficient of expansion. Coefficient of Thermal expansion is the tendency of matter to change in volume in response to a change in temperature, through heat transfer. When a substance is heated, its particles begin moving more and thus usually maintain a greater average separation.

Sun appearing red at sunset is not caused by atmospheric refraction of light. Refraction is essentially a surface phenomenon. During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon. Therefore, light other than red is mostly scattered away. Most of the red light, which is the least scattered, enters our eyes. Hence, the sun and the sky appear red.

Highly concentrated sources of oxygen promote rapid combustion. Fire and explosion hazards exist when concentrated oxidants and fuels are brought into close proximity; however, an ignition event, such as heat or a spark, is needed to trigger combustion. Oxygen itself is not the fuel, but the oxidant.

The Dumas method in analytical chemistry is a method for the quantitative determination of nitrogen in chemical substances based on a method first described by Jean-Baptiste Dumas in 1826.

Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses. DNA is a nucleic acid; alongside proteins and carbohydrates, nucleic acids compose the three major macromolecules essential for all known forms of life.

Steroids estrogen and progestin (synthetic progesterone) are used in contrucptive pills. Steroid hormones help control metabolism, inflammation, immune functions, salt and water balance, development of sexual characteristics, and the ability to withstand illness and injury

Nematocyst is minute, elongated, or spherical capsule produced exclusively by members of the phylum Cnidaria (e.g., jellyfish, corals, sea anemones). Several such capsules occur on the body surface. Each is produced by a special cell called a cnidoblast and contains a coiled, hollow, usually barbed thread, which quickly turns outward (i.e., is everted) from the capsule upon proper stimulation. The purpose of the thread, which often contains poison, is to ward off enemies or to capture prey.

Lactobacillus, also called Döderlein's bacillus, is a genus of Gram-positive facultative anaerobic or microaerophilic rod-shaped bacteria.

Chlorophyll is a green pigment found in cyanobacteria and the chloroplasts of algae and plants. Its name is derived from the Greek words chloros (“green”) and phyllon (“leaf ”). Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to absorb energy from light. It contains magnesium.

In physics, the kinetic energy of an object is the energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.

The ozone layer is a layer in Earth's atmosphere that absorbs most of the Sun's UV radiation. It contains relatively high concentrations of ozone (O3), although it is still very small with regard to ordinary oxygen, and is less than ten parts per million, the average ozone concentration in Earth's atmosphere being only about 0.6 parts per million. The ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 to 30 kilometres (12 to 19 mi) above Earth, though the thickness varies seasonally and geographically

Airlift pumps are often used in deep dirty wells where sand would quickly abrade mechanical parts. (The compressor is on the surface and no mechanical parts are needed in the well). However airlift wells must be much deeper than the water table to allow for submergence. Air is generally pumped at least as deep under the water as the water is to be lifted. (If the water table is 50 ft below, the air should be pumped 100 feet deep).

The passenger-side mirror on a car is typically a convex mirror. In some countries, these are labeled with the safety warning “Objects in mirror are closer than they appear”, to warn the driver of the convex mirror's distorting effects on distance perception. Convex mirrors are preferred in vehicles because they give an upright, though diminished, image. Also they provide a wider field of view as they are curved outwards.

Blue zone is the hottest part of gas flame.

Gamma radiation, also known as gamma rays, refers to electromagnetic radiation of extremely high frequency and therefore high energy per photon. Gamma rays are ionizing radiation, and are thus biologically hazardous.

Ozone layer shields earth from UV radiation - Ionosphere layer allows radio waves to be bounced off and radios to work.

Bacillus Calmette-Guérin is a vaccine against tuberculosis that is prepared from a strain of the attenuated live bovine tuberculosis bacillus, Mycobacterium bovis, that has lost its virulence in humans. BCG is given to new-borns.

Greenhouse gases (sometimes abbreviated GHG) in the atmosphere absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.