Which of the following is the first recombinant vaccine?

The correct answer is C, Planimeter. A planimeter measures the area of any flat shape, however irregular its outline. The user simply traces the boundary of the shape on the map with the instrument's pointer, and a wheel and dial record the area swept, which is then multiplied by the square of the map scale. On a contour map this is how the area enclosed by a contour line, a catchment or a reservoir spread is worked out, so it is a standard tool in survey and irrigation work. A is wrong because areameter is not the accepted name of any such instrument. B is wrong because a clinometer measures the slope of ground or the angle of elevation of a point, not an area. D is wrong because a graphometer is an old surveying instrument used to measure horizontal and vertical angles. Exam tip: planimeter for area, clinometer for slope, planimeter plus contour map for catchment area.

The correct answer is C, 18% Tungsten. High-speed steel is named 18-4-1 after the three metals added to it in that order: 18 per cent tungsten, 4 per cent chromium and 1 per cent vanadium, with iron making up the rest along with a little carbon. Tungsten is the heart of the alloy because it keeps the steel hard even when the cutting edge glows red hot, so drills, milling cutters and lathe tools made from it can cut at high speed without losing their edge. Chromium adds hardness and resistance to rust, and vanadium refines the grain and improves wear resistance. A is wrong because chromium in this grade is 4 per cent, not 1. B is wrong because the 18-4-1 grade has no nickel; nickel goes into stainless steel and into invar. D is wrong because vanadium is the 1 per cent part of the name. Exam tip: 18-4-1 means tungsten 18, chromium 4, vanadium 1.

The correct answer is B, adrenaline. Adrenaline, also called epinephrine, is made by the medulla of the adrenal gland and is the body's emergency hormone; it makes the heart beat faster and stronger and narrows the small blood vessels, so blood pressure rises within seconds. That is why an injection of adrenaline is the first treatment when pressure crashes in shock or in a severe allergic reaction. The same hormone widens the air passages, raises blood sugar and gets the body ready for the fight or flight response. A is wrong because insulin, from the beta cells of the pancreas, lowers blood sugar and is used in diabetes. C is wrong because thyroxine from the thyroid controls the rate of metabolism and growth, and acts slowly over days. D is wrong because vasopressin, the antidiuretic hormone of the pituitary, chiefly saves water by making the kidney reabsorb it. Exam tip: adrenal medulla makes adrenaline, the fight or flight hormone that raises heart rate and blood pressure.

The correct answer is A, Ashwagandha. Ashwagandha, whose botanical name is Withania somnifera, is called winter cherry in English because of the small red berry it bears inside a papery cover; it is also called Indian ginseng. The part used is the root, which in Ayurveda is given as a tonic for weakness, stress and sleeplessness, and the plant's Sanskrit name comes from the horse-like smell of the fresh root. It is a hardy shrub of dry regions, so Rajasthan, Madhya Pradesh and Gujarat are the main growing states; the Nagauri type from Nagaur in Rajasthan and the crop around Mandsaur and Neemuch in Madhya Pradesh are the best known. B is wrong because rose is an ornamental and perfume crop, not a winter cherry. C is wrong because lily is a garden flower grown from bulbs. D is wrong because chandni is an ornamental flowering shrub grown for its white flowers. Exam tip: Ashwagandha, Withania somnifera, winter cherry or Indian ginseng, root used.

The correct answer is B, Fallopian tube. In human beings the sperm meets and fuses with the egg inside the fallopian tube, also called the oviduct.

The ovary releases one egg in a month, and the funnel shaped mouth of the fallopian tube collects it. Sperms swim up from the vagina through the cervix and the uterus into the tube, and fusion usually happens in its wider upper part. The fertilised egg, now a zygote, begins to divide as the tube's lining pushes it along, and reaches the uterus in a few days as a ball of cells that implants in the thick uterine wall and grows there with the help of the placenta.

Option A is wrong because the uterus is where the embryo implants and develops, after fertilisation. Option C is wrong because the ovary only makes and releases the egg. Option D is wrong because the vagina is the passage the sperms enter through.

Exam tip: egg made in the ovary, fertilised in the fallopian tube, developed in the uterus.