Biodiversity plays a major role in providing many ecosystem services. Explain.

Give any two attributes which remain conserved in nature.

Name any four ecosystem services. Who gave the price tags on nature.s life support services? Which is the most important ecosystem service provider?

What are sacred groves? Mention any two examples. Mention its role in conserving biodiversity.

Given below are four statements (i-iv) regarding human blood circulatory system (i) Arteries are thick-walled and have narrow lumen as compared to veins (ii) Angina is acute chest pain when the blood circulation to the brain is reduced (iii) Persons with blood group AB can donate blood to any person with any blood group under ABO system (iv) Calcium ions play a very important role in blood clotting Which two of the above statements are correct ?

Classically, an electron can be in any orbit around the nucleus of an atom. Then what determines the typical atomic size? Why is an atom not, say, thousand times bigger than its typical size? The question had greatly puzzled Bohr before he arrived at his famous model of the atom that you have learnt in the text. To simulate what he might well have done before his discovery, let us play as follows with the basic constants of nature and see if we can get a quantity with the dimensions of length that is roughly equal to the known size of an atom (~ 10^(-10)m) . (a) Construct a quantity with the dimensions of length from the fundamental constants e, m_e, and c . Determine its numerical value. (b) You will find that the length obtained in (a) is many orders of magnitude smaller than the atomic dimensions. Further, it involves c. But energies of atoms are mostly in non-relativistic domain where c is not expected to play any role. This is what may have suggested Bohr to discard c and look for ‘something else’ to get the right atomic size. Now, the Planck’s constant h had already made its appearance elsewhere. Bohr’s great insight lay in recognising that h, m_e, and e will yield the right atomic size. Construct a quantity with the dimension of length from h, me, and e and confirm that its numerical value has indeed the correct order of magnitude.

You are provided with magnesium ribbon and sulphur powder. Explain with the help of an activity that metal oxides are basic and non metal oxide are acidic in nature.