When a DNA molecule replicates, a. The hydrogen bonds along the sugar-phosphate chain are broken. b. The covalent bonds along the sugar-phosphate chain are broken. c. The hydrogen bonds between the nitrogenous base pairs are broken. d. The covalent bonds between the nitrogenous base pairs are broken.

C

Explanation:

The DNA chain breaks the hydrogen bonds between nitrogenous bases when it replicates so that the bases are exposed to DNA polymerase. Breaking the backbone would ruin the molecule.

answer: c

explanation:

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.