General Science Mixed Quiz: Set 22

Inertia is the tendency of a body to stay at rest or keep moving in a straight line, and the measure of that tendency is mass.

Both are tiny algae grown in tanks and sold as protein rich food supplements, and both have been studied as food for astronauts.

Newton's universal law of gravitation states that every two bodies attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them, written F = GMm/d².

The BCG vaccine takes its name from Albert Calmette and Camille Guerin, the two French scientists who developed it from a weakened strain of Mycobacterium bovis.

An optical fibre is a thin thread of glass or plastic with a core of higher refractive index surrounded by a cladding of lower refractive index.

Distillation separates a liquid from a solution or from another liquid by boiling it and condensing the vapour, so it is used when the components differ in boiling point, as in getting pure water from salt water or separating acetone from water.

This is the band of frequencies to which a healthy human ear responds, and the upper limit falls with age.

Opium is the dried latex of the opium poppy, whose botanical name is Papaver somniferum; the second word means sleep bringing.

The potential difference between two points in a circuit is defined as the work done in moving a unit positive charge from one point to the other.

Algae belong to Thallophyta, the simplest division of the plant kingdom. Their body is a thallus, which means it is not divided into root, stem and leaf, and they have no vascular tissue.

James Chadwick discovered the neutron in 1932 by bombarding beryllium with alpha particles and showing that the radiation produced consisted of neutral particles of nearly the same mass as the proton.

Silk comes from the cocoon spun by the caterpillar of a moth. The common silk moth is Bombyx mori, and rearing it is called sericulture.

Carbon occurs in nature in two ways, free and combined. In the free state the element stands alone, as in diamond, graphite and coal; diamond is pure carbon whose atoms are each joined to four others in a rigid three dimensional network, which is why it is the hardest natural…

The fusion of a male gamete with a female gamete is called fertilisation, and the single cell it produces is the zygote.

The lysosome is a small sac bound by a single membrane that is filled with digestive enzymes, so it breaks down food particles taken into the cell and clears out worn out parts of the cell itself.

At normal atmospheric pressure water stays liquid between 0 °C and 100 °C, and 12 °C lies inside that range.

Fat is digested in the small intestine by these two secretions working together.

Arteries are the blood vessels that carry blood away from the heart to the different parts of the body. Because the heart pushes blood into them under high pressure, arteries have thick, muscular and elastic walls and no valves, and they are placed deep in the body.

Testosterone is made by the Leydig cells of the testes and is the main male sex hormone.

Iron is a micronutrient, needed by plants only in very small amounts, and calcium is a macronutrient, needed in large amounts.