Question

Number of DNA molecules in a metaphase chromosome is
A. Many
B. Three
C. One
D. Two

Answer 1

Hint: DNA is composed of atoms called nucleotides. Every nucleotide contains a phosphate group. It is a sugar group, also composed of a nitrogen base. The four kinds of nitrogen bases are adenine (A), thymine (T), guanine (G), and cytosine (C). The request for these bases is the thing that decides DNA's directions, or hereditary code.

Complete answer:
DNA is duplicated during the S period of a cell cycle. Along these lines, during the metaphase stage, every chromosome (i.e., every chromatid pair) will contain two particles of two-fold abandoned DNA (one atom for each sister chromatid) in mitosis. The adaptation of the polynucleotide chains and the mechanism(s) by which this thick pressing is accomplished is not perceived. In this way, the right choice is 'two'.
Hence, option D is correct.

Note: Metaphase chromosomes are composed of the two polynucleotide chains. In this chain, one in every chromatid and 1.7–8.5 cm long in human cells. It is compacted to a deliberate normal thickness of a few hundred mg/ml predictable with values determined from their DNA substance and volume. The essential commitment is, for the most part, accepted to be from electrostatic impacts intervened by connections of monovalent or potentially divalent cations, basically \[K^+\], \[Na^+\], and additionally \[Mg^2+\], because in vitro these cations cause polynucleosomes to crease to a minimized helical adaptation named the 30-nm fiber.