Statement I : A person may suffer from tuberculosis if she/he frequently visits crowded place. Statement II : Bacteria of tuberculosis spread through droplets by sneezing or coughing.
- A.Both the statements are individually true and Statement II is the correct explanation of Statement I
- B.Both the statements are individually true but Statement II is not the correct explanation of Statement I
- C.Statement I is true but Statement II is false
- D.Statement I is false but Statement II is true
Correct answer
Explanation
The correct answer is A. Both statements are true, and the airborne spread of the TB bacterium is exactly why crowded places raise the risk.
Tuberculosis is caused by the bacterium Mycobacterium tuberculosis, discovered by Robert Koch in 1882. When a person with active lung TB coughs, sneezes or even talks, tiny droplets carrying the bacteria are released into the air and can be breathed in by people nearby. Crowded, poorly ventilated places such as packed rooms, buses and slums bring many people close together, so the chance of inhaling these droplets is higher there. TB mainly affects the lungs, and the BCG vaccine is given to infants in India to protect against its severe forms.
B is wrong because Statement II does explain Statement I; it gives the very reason for the risk. C is wrong because Statement II is true. D is wrong because Statement I is also true.
Exam tip: TB = Mycobacterium tuberculosis, droplet (airborne) spread, BCG vaccine; World TB Day is 24 March.
Practice Questions
View allWith reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements :
1. Its fibres can be blended with wool and cotton fibres to reinforce their properties.
2. Containers made of it can be used to store any alcoholic beverage.
3. Bottles made of it can be recycled into other products.
4. Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions.
Which of the statements given above are correct?
- A.1 and 3
- B.2 and 4
- C.1 and 4
- D.2 and 3
Show answer
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.
Read the full explanation →Consider the following pairs :
Objects in space : Description
1. Cepheids : Giant clouds of dust and gas in space
2. Nebulae : Stars which brighten and dim periodically
3. Pulsars : Neutron stars that are formed when massive stars run out of fuel and collapse
How many of the above pairs are correctly matched?
- A.Only one
- B.Only two
- C.All three
- D.None
Show answer
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- A.Observation and understanding of the Universe
- B.Study of the solar and the lunar eclipses
- C.Placing satellites in the orbit of the Earth
- D.Origin and evolution of living organisms on the Earth
Show answer
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- A.F is maximum when v and B are parallel to each other.
- B.F is maximum when v and B are anti-parallel to each other.
- C.F is maximum when v and B are perpendicular to each other.
- D.The force F is independent of the angle between v and B.
Show answer
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- A.an isosceles triangle
- B.an equilateral triangle
- C.a straight line
- D.a scalene triangle
Show answer
L4 lies on Earth's orbit 60° ahead of the Earth, so it is as far from the Sun as from the Earth.
Read the full explanation →