General Science MCQ Practice

• Correct option: C (Kidney trouble).
• Key concept: Dialysis removes waste products and extra fluids when kidneys fail to perform these tasks.
• Dialysis is not for liver, lung, or heart diseases, where the primary issue is different organ function, not waste clearance.
• Formula/logic: If renal failure impairs filtration, dialysis provides artificial filtration.
• Exam tip: When a question mentions “dialysis,” think kidneys first.
• Why others are incorrect: A, B, D involve non-renal conditions; dialysis targets kidney function, not liver/lung/heart.

• Correct concept: Seismology studies earthquakes and the propagation of seismic waves (P-waves, S-waves) through the Earth.
• Key idea: Earth's elastic response to stress, measured by magnitude scales (e.g., log scales like Richter/Mw).
• Formula hint: Magnitude often uses a logarithmic relation to seismic amplitude (log10 of ground motion).
• Why others are wrong: Atmosphere = meteorology; Fossil = paleontology; Silkworm breeding = sericulture.
• Exam tip: If a question asks about “waves through Earth,” choose Seismology.

• Why yellow is not a primary: In additive color (light), the primary colors are red, green, blue. Yellow is produced by mixing red and green, so it is a secondary color.
• Key concept: RGB additive color model; red + green = yellow.
• Other options: Red, Blue, and Green are primary colors in the additive system, hence they are incorrect choices for “not a primary.”
• Exam tip: If two colors mix to form the third, the third is not a primary in additive color theory.

• Mercury contamination in Minamata Bay led to severe mercury poisoning in humans through fish and shellfish consumption. The toxin was mainly methylmercury, a potent neurotoxin that bioaccumulates in food chains.
• Key concept: bioaccumulation and neurotoxicity of mercury from industrial waste.
• Tip: Remember “Minamata” is famous for mercury poisoning symptoms like numbness and motor disturbance.
• Why others are incorrect: Lead, cyanide, and arsenic caused other poisoning cases; they were not the primary pollutant in this incident.

Correct option: C

• Why: Aerosols act as surfaces for heterogeneous chemical reactions that release chlorine and bromine radicals, which catalytically destroy ozone in the stratosphere.
• Key concept: Ozone (O3) is destroyed by catalytic cycles such as Cl + O3 → ClO + O2 and ClO + O → Cl + O2, amplified on aerosol/PSC surfaces.
• Other options: Hydrogen sulfide, smoke, and hydrogen gas do not significantly deplete stratospheric ozone.

• Why: A bus accelerates forward. Passengers tend to keep their state of rest (inertia of rest) while the bus moves, so they lean backward relative to the bus.
• Key concept: Newton's first law of motion — object at rest stays at rest unless acted on by a net external force; a change in velocity is resisted.
• Formula/idea: If a = acceleration, the tendency to resist change in motion causes a backward tilt when the bus speeds up.
• Exam tip: Remember inertia types: rest vs. motion; here the initial state is rest, so inertia of rest explains backward lean.
• Why others are incorrect: Momentum is about moving objects; gravity is vertical; inertia of motion would apply if the bus suddenly stopped.

• Correct answer: Bangalore — ISRO's headquarters is located in Bengaluru (formerly Bangalore).
• Key concept: Station/ HQ location of a space agency often reflects administrative center and governance, not launch sites.
• Why correct: Bangalore is where ISRO's central administration (HQ) sits, while Trombay, Bombay, and Hyderabad are not the HQ.
• Tip: Remember ISRO HQ = Bengaluru; launch sites (Sriharikota, etc.) are elsewhere.

• Key concept: Vitamin A is essential for rhodopsin in retina. Deficiency causes nyctalopia (night blindness).
• Why correct: Lack of Vitamin A impairs vision in low light, leading to poor night vision.

• Why correct: Gerontology studies aging and problems common in elderly people, including diseases, geriatrics aspects, and aging physiology.
• Key concept: Aging biology and health care for older adults; focus is not on youth or non-living science.
• Why others are incorrect:
  • Cytology = study of cells.
  • Geology = study of Earth’s materials.
  • Zoology = study of animals.
• Exam tip: If the topic mentions elderly or aging, choose Gerontology/geriatrics.