RRB NTPC GK Questions 2026

Every living cell needs a cell membrane, and plant cells add a rigid cell wall outside it. The cell membrane, or plasma membrane, is the thin, selectively permeable boundary of every cell; it controls what enters and leaves.

The Precambrian covers all of Earth's history from its formation about 4.6 billion years ago to the start of the Cambrian about 541 million years ago.

The animal cell membrane is a phospholipid bilayer with proteins set in it and cholesterol between the lipid molecules. The fluid mosaic model of Singer and Nicolson (1972) describes the membrane as a double layer of phospholipids, whose water-loving heads face outward and water-fearing tails face inward.

The Caspian has no natural outlet to any ocean, so it is a landlocked water body, in fact the largest inland body of water on Earth.

Carbon monoxide reacts with neither acids nor bases to form a salt and water, so it is a neutral oxide.

Taking A as the reference level and ignoring air resistance, all the kinetic energy given at A turns into potential energy at the top, B. Mechanical energy is conserved when only gravity does work.

In each of the four changes a substance combines with oxygen from the air, which is oxidation.

Statements I and II are standard rules for oxidation numbers, but Statement III reverses what happens to a reducing agent.

Sleeping sickness, or African trypanosomiasis, is caused by the protozoan Trypanosoma brucei. Trypanosoma is a flagellated protozoan that lives in the blood.

Melanin absorbs the ultraviolet rays of sunlight and shields the DNA of skin cells from damage. Melanin is made by cells called melanocytes in the lower layer of the epidermis.

This is the order of the taxonomic ranks from the broader group to the narrower one. The full hierarchy set out by Linnaeus and used today runs Kingdom, Phylum (Division in plants), Class, Order, Family, Genus and Species.

Orthophosphoric acid, H 3 PO 4, has three replaceable hydrogen ions, so it is tribasic. The basicity of an acid is the number of hydrogen ions one molecule can give up in water.

Lime water is a solution of calcium hydroxide, Ca(OH) 2, not calcium carbonate.

Liquid pressure at a depth is P = hρg, so a taller column presses harder on the base. In P = hρg, h is the height of the liquid above the point, ρ is the density of the liquid and g is the acceleration due to gravity.

Photosynthesis gives off oxygen, and oxygen is what aerobic respiration needs to release energy from food. In photosynthesis, green plants use sunlight, carbon dioxide and water to make glucose, and release oxygen, which comes from the splitting of water.

Parallels shrink as they move towards the poles, so the 0° parallel, the Equator, is the longest of all. Parallels of latitude are circles drawn parallel to the Equator.

The dogfish is a small shark, and sharks are true fishes of the class Pisces. Pisces are aquatic vertebrates that breathe through gills, swim with fins and usually have scales.

Bile breaks fat into tiny droplets and lipase then splits those droplets into fatty acids and glycerol. Bile is made by the liver, stored in the gall bladder and poured into the duodenum.

Curd contains lactic acid, which reacts with copper and brass to form poisonous salts, so it should not be stored in them.

Weather maps and reports in India give atmospheric pressure in millibars, the same value as hectopascals. Air pressure is the weight of the air column pressing on a unit area.