General Science Mixed Quiz: Set 117

With equal length and area, the wire of lower conductivity, aluminium, has the higher resistance. Resistance is R = ρl/A, where ρ is resistivity, and resistivity is the reciprocal of conductivity (ρ = 1/σ).

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.

Litmus is a natural dye extracted from certain lichens, especially species of Roccella. A lichen is a partnership between a fungus and an alga (or a cyanobacterium): the alga makes food by photosynthesis, while the fungus gives shelter and absorbs water and minerals.

Meiosis makes gametes that differ from one another, and fertilization joins a gamete from each of two parents, so every offspring gets a new mix of genes.

Thomson. Working with cathode rays in a discharge tube in 1897, he showed that the rays were a stream of negatively charged particles far lighter than any atom, and he measured their charge to mass ratio, which established the electron as the first known subatomic particle.

On a level curve, friction alone supplies the centripetal force, so a cyclist slips when the needed force exceeds the maximum friction.

Bryophytes such as Marchantia, Riccia, Funaria and Sphagnum grow on soil, rocks and tree trunks, but their male gametes are flagellate and must swim through a film of water to reach the egg, so fertilisation cannot take place in dry conditions.

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.

Vision is caused by the electric field of light acting on the light-sensitive molecules of the retina. Light is an electromagnetic wave in which electric and magnetic fields oscillate at right angles to each other and to the direction of travel.

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.

Root hairs are thin outgrowths of the root's epidermal cells that greatly increase the area for absorbing water and minerals.

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.

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.

Three parts of oxygen-16 and one part of oxygen-18 give an average of (3 × 16 + 1 × 18) ÷ 4 = 66 ÷ 4 = 16.5 u. Isotopes are atoms of the same element with the same atomic number but different mass numbers, because they have different numbers…

Common fertilisers supply nitrogen, phosphorus and potassium (NPK); iron is a micronutrient that is usually not part of them. Plants need nitrogen, phosphorus and potassium in large amounts, so these are called primary macronutrients, and fertilisers such as urea, DAP, MOP and NPK mixtures are made to supply them.

Moving a substance from low to high concentration is uphill work, and the cell pays for it with ATP.

A perfectly horizontal rope has no upward component of tension, so no finite tension can hold up the 200 N weight with the rope fully straight.

If you hold a current-carrying straight wire in your right hand with the thumb pointing along the current, your curled fingers show the direction of the magnetic field lines around it.

By bombarding beryllium with alpha particles he obtained a penetrating radiation that could not be bent by electric or magnetic fields, and he showed it to consist of neutral particles of about the mass of a proton, for which he received the Nobel Prize in Physics.

Ferns and their relatives, such as Selaginella, Lycopodium, Equisetum, Pteris, Adiantum and Marsilea, are the first plants with xylem to conduct water and minerals and phloem to conduct food, and the first with a true root, stem and leaf; for that reason they are also called the vascular cryptogams.