During the prophase the nucleoli in the nucleus disappear. The chromatin fibers become tightly ccoiled and condense into chromosomes. Chromosomes line up in pairs and are joined at the centromere. In the cytoplasm, the spindle fibers begin to formand are made of microtubules.
Carbon is the atom, which is necessarily find in the living organism.
All the living organisms are made up of biomolecules. All the biomolecules are organic compounds. The substance cannot be consider as living, if it lacks nucleic acids. There are two types of nucleic acids DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), both have a structure made up of carbon rings and chains.
Other than nucleic acids, proteins, enzymes, hormones etc are also made up of carbon. So, all the living cells, or dead remain of organism must have carbon atom.
Hence, the correct answer is option D. carbon.
Different forms of a given gene are known as "alleles". Alleles are essential for the formation of life and add to diversity both within and outside the organism itself in many ways.