General Science Questions and Answers

Answer: B

The first five elements of the periodic table, in order of atomic number, are H, He, Li, Be and B - hydrogen (1), helium (2), lithium (3), beryllium (4) and boron (5).

The table is arranged by atomic number, which is the number of protons in the nucleus, not by atomic mass or by any chemical property.

Answer: A

Hormones are produced by the endocrine glands - the ductless glands that secrete directly into the bloodstream.

The pituitary, thyroid, adrenals, pancreas and gonads are all endocrine glands, so naming any one of them alone is incomplete.

Answer: B

Protoplasm is called the physical basis of life - the living substance of the cell, comprising the cytoplasm and the nucleus together.

The term was coined by Purkinje in 1839 and given its famous description by Thomas Huxley. Cytoplasm is only the part outside the nucleus.

Answer: D

To an astronaut, outer space appears black.

The sky is blue on earth because air molecules scatter sunlight; in the vacuum of space there is nothing to scatter it, so no light reaches the eye except directly from the sun, the stars and lit surfaces. The sun therefore shines against a black sky.

Answer: D

A fluxgate magnetometer measures both the magnitude and the direction of a magnetic field.

It works by driving a core into saturation with an alternating current; any external field makes the saturation asymmetric, and the asymmetry gives the field component along the axis. Three orthogonal sensors give the full vector.

Answer: A

ADH stands for antidiuretic hormone, also called vasopressin.

It is released from the posterior pituitary when the blood becomes too concentrated, and makes the kidney tubules reabsorb water, so less urine is passed. Its absence causes diabetes insipidus.

Answer: D

Sulphuric acid is H₂SO₄ - two hydrogen atoms, one sulphur and four oxygen.

It is a dibasic strong acid and the most produced industrial chemical in the world, used in fertilisers, refining, dyes and batteries. K₂SO₄ and Na₂SO₄ are its salts and SO₂ is an oxide of sulphur.

Answer: C

Clove is a dried flower bud of Syzygium aromaticum, picked before it opens and dried until brown.

Its aroma comes from eugenol, which makes up most of clove oil and is used in dentistry as a local anaesthetic.

Answer: B

Christiaan Barnard performed the world's first human heart transplant, at Groote Schuur Hospital in Cape Town on 3 December 1967.

The patient, Louis Washkansky, lived eighteen days before dying of pneumonia. William Harvey had described the circulation of the blood three centuries earlier.

Answer: C

The microscope is the instrument used to study germs, magnifying them hundreds or thousands of times.

A periscope sees over obstacles, a stethoscope listens to the heart and lungs, and a cardiograph records the heart's electrical activity.