Adna nucleotide does not contain
(a) adenine
(b) thymine.
(c) uracil.
(d) cytosine

Uracil.

Explanation:

DNA is present as genetic material in all the living organism except some viruses. DNA is made of the polymers of nucleotides and shows anti parallel polarity.

The structure of nucleotide consists of pentose sugar, nitrogenous bases and phosphate group.The nitrogenous base pair of DNA contains adenine, thymine, cytosine and guanine. Uracil is present in the RNA not in the DNA molecule.

Thus, the correct answer is option (C).

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation: