General Science GK Questions with Answers

In 1609 Kepler showed that the planets move around the Sun in elliptical orbits, with the Sun at one focus of the ellipse.

Liver cells turn the toxic ammonia released from the breakdown of amino acids into urea through the ornithine cycle, also called the urea cycle.

Light passes through the condenser to the specimen, is picked up by the objective lens, travels up the body tube and reaches the eye through the eyepiece.

It binds oxygen at its iron-containing haem groups and carries some carbon dioxide on its protein chains. Each haemoglobin molecule has four polypeptide chains and four haem groups, and each haem iron can hold one oxygen molecule, forming oxyhaemoglobin in the lungs.

They are the proteins around which DNA winds to form chromatin in the nucleus of eukaryotic cells. Histones are small basic proteins, rich in the positively charged amino acids lysine and arginine, which attract the negatively charged phosphate groups of DNA.

Hooke's law says stress is directly proportional to strain, and that holds only up to the proportional limit, where the curve is a straight line.

A constellation is a group of stars that appears to form a shape when seen from the earth, but its stars usually lie at very different distances from us.

In an ideal gas the molecules move with a whole range of speeds, so this statement is false. The kinetic theory treats an ideal gas as a large number of tiny molecules in random motion that collide elastically with one another and with the walls.

The British physicist said these words in a lecture in January 2016, using his own work on black holes as a message of hope for people facing depression.

Tincture of iodine is made from iodine, potassium iodide, alcohol and water; acetone is not one of its ingredients. A tincture is a solution in alcohol.

Natural rubber is a polymer of isoprene, a hydrocarbon, and contains no sugar units at all. Natural rubber is cis-1,4-polyisoprene, obtained from the latex of the rubber tree Hevea brasiliensis; its monomer isoprene (2-methyl-1,3-butadiene) has the formula C5H8.

Lead nitrate decomposes on heating into lead(II) oxide, nitrogen dioxide and oxygen. The balanced equation is 2Pb(NO3)2 → 2PbO + 4NO2 + O2.

Both statements describe how cancer starts and how it spreads, and both are correct. Cancer is uncontrolled division of cells.

Phosphorus has five electrons in its outer shell and shows two common valencies, 3 and 5. Phosphorus, atomic number 15, has the electronic configuration 2, 8, 5.

This statement is false, because yeast is one of the few fungi that are unicellular. In Whittaker's five-kingdom system, fungi form a separate kingdom.

Only a pressure greater than the osmotic pressure of seawater can push pure water backwards through the membrane. In ordinary osmosis, water moves through a semipermeable membrane from the dilute side to the concentrated side.

Silver sits near the bottom of the reactivity series and does not combine with oxygen even when heated in air.

Bacteria on the floor break down the urea in urine and release ammonia, which has a sharp, pungent smell. Urea, CO(NH2)2, is the main nitrogenous waste of humans.

It is very cold, chemically inert and cheap, which makes it the standard coolant for preserving cells and tissues. Liquid nitrogen boils at about −196 °C. At such low temperatures the chemical and enzyme activity inside cells almost stops, so tissues can be kept unchanged for years.

Both statements describe how nucleases are used as tools of recombinant DNA technology. Nucleases are enzymes that break the phosphodiester bonds of DNA.