General Science Mixed Quiz: Set 132

Living things are built up level by level: molecules such as proteins form cells, cells form tissues, tissues form organs, organs form organ systems, and these together make an organism.

The islets of Langerhans are patches of endocrine tissue in the pancreas, and their beta cells secrete insulin, which lowers the level of glucose in the blood by helping cells take it up and by storing the surplus as glycogen; a lack of insulin causes diabetes mellitus.

Both statements are true, and the airborne spread of the TB bacterium is exactly why crowded places raise the risk.

The 2011 FSSAI labelling rules made the list of ingredients, nutrition information and the vegetarian or non-vegetarian mark compulsory, but not medical advice on allergies.

Tin is a chemical element (symbol Sn, atomic number 50), a pure substance made of only one kind of atom, so it is not a mixture.

All three are underground modified stems: the potato is a stem tuber, and onion and garlic are bulbs. A stem can be told from a root by its nodes and buds.

By Archimedes' principle, the buoyant force equals the weight of the water displaced by the sphere. A fully immersed body displaces its own volume of water, here 2 × 10⁻⁴ m³.

Friction acts only where two surfaces touch, while a magnet can push or pull an object across a gap. Forces are grouped by whether the bodies must touch.

In glass, violet light has the shortest wavelength and the highest refractive index, so it bends the most; dispersion is a result of refraction.

Meiosis halves them in the gametes, and fertilisation restores them in the offspring. Each parent makes gametes by meiosis, so a human egg or sperm carries 23 chromosomes instead of 46.

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.

For an ideal gas in a fixed volume at a fixed temperature, pressure is proportional to the number of molecules, so half the molecules give half the pressure.

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.

Crown gall is caused by the bacterium Agrobacterium tumefaciens, which enters through a wound near the base, or crown, of the stem and makes the plant grow rough tumour-like swellings there.

The dogfish is a small shark, and sharks are true fishes of the class Pisces. Pisces are aquatic vertebrates that breathe through gills, swim with fins and usually have scales.

The de Broglie wavelength depends only on momentum, so equal wavelengths mean equal momenta. In 1924 Louis de Broglie proposed that every moving particle has a wave linked to it, with wavelength λ = h/p, where h is Planck's constant and p is the linear momentum.

The English physician showed in 1796 that deliberate inoculation could protect a person against smallpox. Jenner noticed that milkmaids who had caught the mild disease cowpox did not get smallpox.

L4 lies on Earth's orbit 60° ahead of the Earth, so it is as far from the Sun as from the Earth.

Carbon monoxide binds to haemoglobin far more strongly than oxygen does and forms carboxyhaemoglobin, so the blood cannot pick up oxygen even though breathing goes on; the gas is colourless and odourless, which makes it the more dangerous, and it is produced by the incomplete burning of fuel in closed…

The thyroid is a butterfly-shaped gland in the neck, in front of the windpipe, and is the largest of the ductless or endocrine glands; it secretes thyroxine, for which iodine is essential, and the hormone controls the rate of metabolism, growth and development.