The non-metal used in the purple coloured solution applied on wounds as an antiseptic is
- A.Chlorine
- B.Iodine
- C.Bromine
- D.Sulphur
Correct answer
Explanation
The correct answer is B, Iodine. Iodine is the non-metal in the antiseptic painted on cuts and wounds, sold as tincture of iodine, which is a solution of iodine in alcohol. Solid iodine is a shining dark violet-black solid and its vapour is deep purple, which is the colour the question points to; it is the one non-metal with a clear metallic lustre. Iodine kills germs on the skin, and the same element is needed by the thyroid gland to make its hormones, so too little iodine in food causes goitre. That is why kitchen salt sold in India is iodised. A is wrong because chlorine is used to disinfect drinking water and in bleaching powder, not as a wound paint. C is wrong because bromine is a reddish-brown liquid used in dyes and photographic chemicals. D is wrong because sulphur is a yellow non-metal used in ointments for skin disease and in making sulphuric acid. Exam tip: tincture of iodine is iodine dissolved in alcohol, and a shortage of iodine causes goitre.
Practice Questions
View allThe fact that the planets move around the Sun, not in circles but in ellipses, was first demonstrated by
- A.Galileo
- B.Martin Luther
- C.Johannes Kepler
- D.Copernicus
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In 1609 Kepler showed that the planets move around the Sun in elliptical orbits, with the Sun at one focus of the ellipse.
Read the full explanation →Which one of the following statements is correct?
- A.Urea is produced in liver.
- B.Urea is produced in blood.
- C.Urea is produced from digestion of starch.
- D.Urea is produced in lung and kidney.
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Liver cells turn the toxic ammonia released from the breakdown of amino acids into urea through the ornithine cycle, also called the urea cycle.
Read the full explanation →Which one of the following is the correct sequence of passage of light in a compound microscope?
- A.Condenser-Objective lens-Eyepiece-Body tube
- B.Objective lens-Condenser-Body tube-Eyepiece
- C.Condenser-Objective lens-Body tube-Eyepiece
- D.Eyepiece-Objective lens-Body tube-Mirror
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Light passes through the condenser to the specimen, is picked up by the objective lens, travels up the body tube and reaches the eye through the eyepiece.
Read the full explanation →Which one of the following statements regarding haemoglobin is correct?
- A.Haemoglobin present in RBC can carry only oxygen but not carbon dioxide.
- B.Haemoglobin of RBC can carry both oxygen and carbon dioxide.
- C.Haemoglobin of RBC can carry only carbon dioxide.
- D.Haemoglobin is only used for blood clotting and not for carrying gases.
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It binds oxygen at its iron-containing haem groups and carries some carbon dioxide on its protein chains. Each haemoglobin molecule has four polypeptide chains and four haem groups, and each haem iron can hold one oxygen molecule, forming oxyhaemoglobin in the lungs.
Read the full explanation →Which one of the following statements regarding histone proteins is correct?
- A.Histones are proteins that are present in mitochondrial membrane.
- B.Histones are proteins that are present in nucleus in association with DNA.
- C.Histones are proteins associated with lipids in the cytosol.
- D.Histones are proteins associated with carbohydrates in the cytosol.
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They are the proteins around which DNA winds to form chromatin in the nucleus of eukaryotic cells. Histones are small basic proteins, rich in the positively charged amino acids lysine and arginine, which attract the negatively charged phosphate groups of DNA.
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