Answer:
A. DNA polymerase
Explanation:
DNA polymerases (I,II,III) proofread the DNA, which helps to catch errors. Errors can be fatal to expression, creating misformed proteins or unclear information, so this is necessary.
Fun facts - the coronavirus is a retrovirus, so it doesn't proofread. That makes it much harder to find a vaccine, because it can generate new strains by the very fact of not proofreading.
The synthetic estrogen-like hormone is classified as a xenohormone. Xenohormones have hormone like affects when absorbed or ingested by animals. As a result, they cause a variety endocrine complications. These types of compounds in the environment can easily find their way into the fishes that humans consume and eventually cause endocrine problems in the human population.
86 % of plants and animals
The right answr is hydrogen bonds
The hydrogen bond or hydrogen bridge is an intermolecular force involving a hydrogen atom and an electronegative atom such as oxygen, nitrogen and fluorine. The intensity of a hydrogen bond is intermediate between that of a covalent bond and that of van der Waals forces.
The helices of the DNA (both strands) are maintained by hydrogen bonds.