General Science Mixed Quiz: Set 193

For any position of a real object in front of a convex mirror, the image forms behind the mirror between P and F. A convex mirror bulges outward, and its focus and centre of curvature lie behind it.

Bacillary dysentery, also called shigellosis, is caused by bacteria of the genus Shigella, which invade the lining of the large intestine and produce frequent stools with blood and mucus, along with fever and cramps; it spreads through contaminated water and food.

Ferromagnetism needs the atomic magnets of a substance to line up together in fixed regions called domains, and this happens only in the ordered structure of a solid.

RNA carries adenine, guanine, cytosine and uracil, and the uracil occupies the place that thymine holds in DNA, pairing with adenine in the same way.

. Cathode rays behave the same whatever gas is in the tube, so the statement that they depend on the gas is not correct.

An anemometer measures how fast the wind is blowing; its name comes from the Greek word anemos, meaning wind.

Tidal volume is the volume of air breathed in or out in one normal, quiet breath, about 500 mL in a healthy adult.

RTGs power spacecraft using heat from the natural decay of plutonium-238; they are not reactors and involve no fission. In an RTG, a radioactive isotope gives off heat as it decays on its own.

Among the options it is the only vitamin made by bacteria; no plant or animal cell can make it, so bacteria, including those in the gut, are its source.

Pure alumina melts at a very high temperature, so in the Hall and Heroult process it is dissolved in molten cryolite, sodium hexafluoroaluminate, usually with some fluorspar, which lowers the working temperature of the bath and makes the melt a far better conductor of electricity.

Particles in a colloid are large enough to scatter a beam of light, which makes the path of the beam visible.

When the oxygen supply is short, the carbon of the fuel is only partly oxidised and carbon monoxide is formed instead of carbon dioxide.

In myopia, or short-sightedness, a person sees near objects clearly but distant objects look blurred because their image forms in front of the retina.

PET fibre (polyester) is blended with wool and cotton, and PET bottles are widely recycled into new products. Polyethylene terephthalate is a polyester made from ethylene glycol and terephthalic acid.

Sponges are the members of phylum Porifera, a name that means "pore bearers", because their bodies are full of tiny pores called ostia.

This is the order of the taxonomic ranks from the broader group to the narrower one. The full hierarchy set out by Linnaeus and used today runs Kingdom, Phylum (Division in plants), Class, Order, Family, Genus and Species.

The urinary bladder is a hollow muscular sac made of smooth muscle and a stretchable lining; it has no cartilage.

The cervix is the narrow lower neck of the uterus and belongs to the female reproductive system. In the male, sperms are made in the testes, which lie in the scrotum outside the body because sperm formation needs a temperature a little lower than body temperature.

Covaxin is an inactivated virus vaccine and Sputnik V is a viral vector vaccine, but Covishield is a viral vector vaccine, not an mRNA vaccine.

Isoenzymes, also called isozymes, are different molecular forms of an enzyme that speed up the same chemical reaction but differ in their amino acid sequence.