Question

If a DNA molecule has 2000 BP, then calculate the number of sugar and phosphate molecules.
A. 2000 sugar and 2000 phosphate molecules
B. 2000 sugar and 4000 phosphate molecules
C. 4000 sugar and 2000 phosphate molecules
D. 4000 sugar and 4000 phosphate molecules

Answer 1

Hint: DNA is deoxyribonucleic acid. All the 23 pair chromosomes carry DNA. These are double-stranded coiled helices. These have two polypeptide strands. The model of DNA was given by Watson and Crick. X-Crystallography was used to identify the structure.

Complete answer: Human genome is a set of nucleic acids sequence in the case of humans which is encoded as DNA with all 23 pairs of chromosomes in cell nuclei. DNA is deoxyribonucleic acid. It is composed of two polynucleotide chains. These coils around each other forming a helix. It carries information about the genetic development, growth, and functioning of an individual. These also carry the physical trait genes from the parents.
A DNA molecule has a sugar, phosphate and purine/pyrimidine group.
A DNA molecule has 2000 base pairs, this means there are 2000 base pairs of one strand of DNA.
But DNA being a double chain, it will have 4000 base pairs on both the strands.
Every base is connected to a sugar molecule and every sugar molecule is attached to a phosphate group.
Thus there will be 4000 base pairs, 4000 sugars and 4000 phosphate molecules.
Option A: 2000 sugar and 2000 phosphate molecules: there will be 2000 sugar and phosphate molecules in half of the polypeptide.
Option B: 2000 sugar and 4000 phosphate molecules: there will be an equal number of sugar and phosphate molecules as one sugar is attached to one phosphate molecule.
Option C: 4000 sugar and 2000 phosphate molecules: 2000 sugar and 4000 phosphate molecules: there will be an equal number of sugar and phosphate molecules as one sugar is attached to one phosphate molecule.
Option D: 4000 sugar and 4000 phosphate molecules: There will be 4000 sugar and phosphate molecules as there is one sugar attached to one phosphate molecule.
Hence, the answer is option D: 4000 sugar and 4000 phosphate molecules

Note: Human genome is a complete set of nucleic acids sequence in humans which is encoded as DNA with all 23 pairs of chromosomes in cell nuclei. DNA is deoxyribonucleic acid. It is composed of two polynucleotide chains. These coils around each other forming a helix. It has a diameter of 2nm. The DNA differs at only 0.1% in the whole genome of the world.