General Science GK Questions with Answers – Page 100

Nothing is oxidised when a soda bottle is opened; the pressure inside simply falls, the dissolved carbon dioxide becomes less soluble and escapes as bubbles.

Naphthalene is an aromatic hydrocarbon, C10H8, with a very high proportion of carbon, so the air around the flame cannot supply enough oxygen to burn all of it to carbon dioxide.

The balanced equation for the complete combustion of glucose is C6H12O6 plus 6O2 gives 6CO2 plus 6H2O, so one mole of glucose needs six moles of oxygen gas.

Ultraviolet light is a transverse wave, not a longitudinal one, so this statement is the wrong one. In an electromagnetic wave the electric and magnetic fields vibrate at right angles to each other and to the direction the wave travels, which is the definition of a transverse wave.

They are called the suicide bags of the cell because they are packed with digestive enzymes that can break down the cell's own material.

An alkene has a carbon-carbon double bond, and adding hydrogen across that bond turns it into the corresponding alkane.

When electricity is passed through a sealed tube holding neon at low pressure, the gas atoms are excited and give out a bright orange-red glow, which is why advertising signs are still called neon signs.

Emerald is the deep green variety of the mineral beryl, a beryllium aluminium silicate, so beryllium is part of its very formula.

The English physician William Harvey showed by experiment and measurement that blood is not made afresh and used up in the tissues, as was then believed, but moves in a closed circuit, driven by the heart acting as a pump, and he published this in 1628 in his book on…

The opening between the left atrium and the left ventricle is guarded by a valve with two flaps or cusps, which is why it is called the bicuspid valve; it is also known as the mitral valve because its shape resembles a bishop's mitre.

Antidiuretic hormone, also called vasopressin, is released by the posterior lobe of the pituitary gland and makes the distal tubule and the collecting duct of the nephron pull water back into the blood.

Filtration at the glomerulus is blind: it pushes out useful glucose and amino acids along with the waste.

When the body breaks down more protein than it needs, the amino acids are stripped of their amino group and the ammonia so released is highly poisonous.

A red blood cell lives about one hundred and twenty days. As it ages its membrane grows stiff, and the narrow winding channels of the spleen trap such cells so that the macrophages lining them can break the cells down and salvage the iron of their haemoglobin.

The heartbeat is not started by a nerve from the brain; the heart generates its own rhythm, and the patch of specialised tissue that does so fastest sets the pace for the rest.

In the ABO system the antigens sit on the surface of the red blood cell and the antibodies float in the plasma.

An artery is defined by direction, not by the kind of blood it holds: it carries blood away from the heart.

The nephron is the structural and functional unit of the kidney, and each human kidney holds about one million of them.

It is a leaf-shaped flap of cartilage at the root of the tongue that swings down and covers the opening of the windpipe every time food is swallowed, so that the bolus is guided into the oesophagus instead of the trachea; when it fails we choke and cough.

Most of the carbon dioxide produced by the tissues enters the red blood cells, where the enzyme carbonic anhydrase combines it with water to form carbonic acid, which at once splits into hydrogen and bicarbonate ions; the bicarbonate then travels in the plasma to the lungs, where the reaction is…