Question

Which of the numbered statements below describe an aspect of DNA structure that directly and specifically helped scientists infer a mechanism for DNA replication?

1. Hydrogen bonds between paired nucleotides can be broken to unzip the strands

2. The double helix structure of DNA allows it to be packed very tightly in chromosomes.

3. The uniform diameter of a double helix demonstrates nucleotide base-pairing.

4. The number of genes in a single strand of DNA can be matched to another strand.

5. The negatively charged backbone allows DNA to coil into a double helix.

a. Both statements 1 and 2

b. Both statements 3 and 4

c. Both statements 4 and 5

d. Both statements 1 and 3

e. Both statements 2 and 4

f. Both statements 3 and 5

g. All statements 1,2,3,4, and 5.

Answer 1

Answer) Statement D.

Explanation:.​​​​​​DNA stands for deoxyribose nucleic acid. The negative charge is found on DNA due to presence of phosphate group. The phosphate group has negative charge. The DNA is helical in shape due to presence of hydrogen bonding between the nitrogenous base. The hydrogen bonding is found between purine and pyrimidine. This depicts the diameter of DNA. Histone proteins are present in nucleosomes. These protein wraps DNA around it. And leads to formation of chromosomes from chromatin.

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