Which one of the following air pollutants combines with the haemoglobin of human blood and reduces its oxygen-carrying capacity, leading to suffocation and may cause even death?
- A.Chlorofluorocarbon
- B.Fly ash
- C.Carbon monoxide
- D.Sulphur dioxide
Correct answer
Explanation
The correct answer is C, Carbon monoxide. Carbon monoxide binds with haemoglobin far more strongly than oxygen does, so the blood can no longer carry enough oxygen.
Carbon monoxide (CO) is a colourless, odourless gas produced by the incomplete burning of fuels, for example in vehicle exhausts, charcoal stoves and closed rooms with a fire burning. In the blood it joins haemoglobin to form carboxyhaemoglobin. Haemoglobin's affinity for CO is about 200 to 250 times its affinity for oxygen, and the bond is stable, so even a small amount of CO cuts the blood's oxygen supply. This causes headache, dizziness, suffocation and, in high doses, death.
A is wrong: chlorofluorocarbons damage the ozone layer; they do not bind haemoglobin.
B is wrong: fly ash is a particulate pollutant that harms the lungs.
D is wrong: sulphur dioxide irritates the airways and causes acid rain, but does not combine with haemoglobin.
Exam tip: CO + haemoglobin = carboxyhaemoglobin; affinity about 200 times that of oxygen.
Practice Questions
View allConsider the following :
1. Battery storage
2. Biomass generators
3. Fuel cells
4. Rooftop solar photovoltaic units
How many of the above are considered "Distributed Energy Resources"?
- A.Only one
- B.Only two
- C.Only three
- D.All four
Show answer
Battery storage, biomass generators, fuel cells and rooftop solar units are all small, local sources that generate or store power close to where it is used, which is what Distributed Energy Resources are.
Read the full explanation →Due to some reasons, if there is a huge fall in the population of species of butterflies, what could be its likely consequence/consequences ?
1. Pollination of some plants could be adversely affected.
2. There could be a drastic increase in the fungal infections of some cultivated plants.
3. It could lead to a fall in the population of some species of wasps, spiders and birds.
Select the correct answer using the code given below :
- A.1 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Butterflies are pollinators and also food for many animals, so their decline would hurt pollination and their predators; it has no direct link with fungal diseases of crops.
Read the full explanation →Consider the following statements :
1. Lions do not have a particular breeding season.
2. Unlike most other big cats, cheetahs do not roar.
3. Unlike male lions, male leopards do not proclaim their territory by scent marking.
Which of the statements given above are correct ?
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Lions breed at any time of year and cheetahs cannot roar, but male leopards do mark their territory with scent.
Read the full explanation →Which one of the following National Parks lies completely in the temperate alpine zone?
- A.Manas National Park
- B.Namdapha National Park
- C.Neora Valley National Park
- D.Valley of Flowers National Park
Show answer
Set high in the Garhwal Himalaya of Uttarakhand, roughly between 3,200 and 6,600 metres, it lies wholly in the temperate alpine zone.
Read the full explanation →Consider the following kinds of organisms:
1. Copepods
2. Cyanobacteria
3. Diatoms
4. Foraminifera
Which of the above are primary producers in the food chains of oceans?
- A.1 and 2
- B.2 and 3
- C.3 and 4
- D.1 and 4
Show answer
Cyanobacteria and diatoms carry out photosynthesis, so they are phytoplankton, the primary producers at the base of ocean food chains.
Read the full explanation →