NEET Practice Questions (MCQs) with Answers & Solutions

The text explains: 'The problem is that conventional taxonomic methods are not suitable for identifying microbial species and many species are simply not culturable under laboratory conditions.'

The text states: 'In general, species diversity decreases as we move away from the equator towards the poles.'

The text mentions: 'but a more conservative and scientifically sound estimate made by Robert May places the global species diversity at about 7 million.'

The text states: 'Of the named species, > 70 per cent are animals, of which 70 per cent are insects.'

The text provides the example: 'Colombia located near the equator has nearly 1,400 species of birds...'

The text implies this: 'India, with much of its land area in the tropical latitudes, has more than 1,200 species of birds.' This links high diversity to tropical latitudes.

According to Table 9.1, the relative abundance of Carbon (C) is 18.5% in the human body compared to 0.03% in the Earth's crust, which is a significant difference. While Oxygen is abundant in both, its relative abundance difference is not as striking as carbon and hydrogen. Silicon is abundant in the Earth's crust but negligible in the human body. Calcium also shows a higher percentage in living tissues but not as comparatively high as carbon.

The context states: 'Now if the tissue is fully burnt, all the carbon compounds are oxidised to gaseous form (CO2, water vapour) and are removed. What is remaining is called ‘ash’. This ash contains inorganic elements (like calcium, magnesium etc).' Therefore, magnesium would be found in the ash.

The text states: 'Scientists have found thousands of organic compounds in the acid-soluble pool.' Later, it clarifies that 'They have molecular weights ranging from 18 to around 800 daltons (Da) approximately.' This indicates small molecular weight organic compounds. The acid-insoluble fraction contains macromolecules and membrane fragments.

The NCERT text explicitly states: 'Lipids are not strictly macromolecules. The acid insoluble fraction, has only four types of organic compounds i.e., proteins, nucleic acids, polysaccharides and lipids. These classes of compounds with the exception of lipids, have molecular weights in the range of ten thousand daltons and above.' Lipids are found in the acid insoluble fraction because they form vesicles from broken cell membranes, which are not water-soluble, not primarily due to their macromolecular size.