Nitrogen in a kind of chemical element whose circulation from nature to organism and vise-versa is controlled largely by microbes -analyse the statement.

Select the correct combination of the statements (i-iv) regarding the characteristics of certain organisms. (i) Methanogens are archaebacteria which produce methane in marshy areas (ii) Nostoc is a filamentous blue-green alga which fixes atmospheric nitrogen (iii) Chemosnthetic autotrophic bacteria synthesise cellulose from glucose (iv) Mycoplasma lack a cell wall and can survive without oxygen The correct statements are

Frog's heart when taken out of the body continues to beat for sometime Select the best option from the following statements (A) Frog is a poikilotherm (B) Frog does not have any coronary circulation (C) Heart is "Myogenic" in nature (D) Heart is autoexcitable

Read the following statements regarding the mineral nutrition in plants (1) For the elements that are actively mobilized within the plants, the deficiency symptoms tend to appear first in the young tissues. (2) Manganese competes with iron and magnesium for uptake and with magnesium for binding with enzymes. (3) Manganese inhibits calcium traslocation in shoot apex. (4) Rhodospirillum is aerobic free-living nitrogen fixing microbe. Which of these are correct

An organic compound [A], whose molecular formula is C_(3)H_(6)O , gives iodoform reaction and forms compound [B]. Compound [B], when heated with silver powder, converts into compound [C}. Compound [C] reacts with dil. Sulphuric acid and mercuric sulphate to obtain compound [D], which gives Aldol condensation reaction. Write down the names of all compounds from [A] to [D] and also write the chemical equations for each step.

Let S be the set of points whose abscissas and ordinates are natural numbers . Let P in S such that the sum of the distance of P from (8,0) and (0,12) is minimum among all elements in S . Then the number of such points P in S is