General Science Previous Year Questions (PYQ) with Answers

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

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.

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

The Hardy-Weinberg principle states the opposite: allele frequencies in a population stay stable, that is constant, from generation to generation.

A prokaryotic cell has no true nucleus, so its genetic material is not wrapped in a nuclear membrane. Bacteria and cyanobacteria are prokaryotes.

Hallucinations, most often hearing voices that others cannot hear, are a core symptom of schizophrenia. Schizophrenia is a serious mental disorder in which a person loses touch with reality.

The Calvin cycle fixes carbon dioxide into sugar without needing light directly, so it forms the light-independent (dark) reactions. Photosynthesis happens in two stages inside the chloroplast.

Female Anopheles mosquitoes bite humans because they need blood to mature their eggs, and the malaria parasite can cross the placenta.

A mature mammalian red blood cell has no nucleus, ribosomes or mitochondria, so it can neither make proteins nor divide.

Collagen is the main structural protein of cartilage, and it is a fibrous protein, not a globin. Globins are compact, folded proteins that hold a haem group and carry or store oxygen.

Mitosis keeps the chromosome number unchanged, so it never makes cells haploid; that is the work of meiosis. In mitosis one parent cell divides once and gives two daughter cells that are genetically identical to it.

Movement of ions through protein channels is facilitated diffusion, a passive process that needs no energy from ATP. Active transport moves substances against their concentration gradient, from low to high concentration, using carrier proteins and energy, usually from ATP.

Neither statement is correct: only starch is a mixture of amylose and amylopectin, and only glycogen is stored in liver cells.

Anthropology, from the Greek 'anthropos' (human) and 'logos' (study), is the science of human beings: how societies and cultures began, how they changed and how people live today.

In the Brønsted–Lowry theory an acid is any substance that gives away a proton, that is a hydrogen ion (H⁺), to another substance.

When an acid such as hydrochloric acid dissolves in water, it splits into ions: hydrogen ions (H⁺, which join water molecules as hydronium ions, H₃O⁺) and negative ions such as chloride (Cl⁻).

The mass of one mole of any substance, expressed in grams, is by definition its molar mass. One mole contains the Avogadro number of particles, about 6.022 × 10 23, so the molar mass links the mass we can weigh to the number of atoms or molecules present.

When an electric current is passed through brine, a concentrated aqueous solution of sodium chloride, the salt decomposes. Chlorine gas is given off at the anode and hydrogen gas at the cathode, while sodium hydroxide is left in the solution near the cathode.

Molarity and molality are both standard ways of stating how much solute is present in a solution.

The four terrestrial planets do lie between the Sun and the asteroid belt, but they are dense, not light, and their weak gravity could not hold on to escaping gases.