<h3><u>Answer and explanation;</u></h3>
- DNA is a double stranded molecule. Covalent and hydrogen bonds pray important roles in the functioning of DNA molecules.
- <em><u>Covalent bonds occur within each linear strand and strongly bond the nucleotide bases, sugars, and phosphate groups occurring both within each component and between components.</u></em>
- <em><u> Hydrogen bonds occur between the two strands and involve a base from one strand with a base from the second in complementary pairing.</u></em>
- Hydrogen bonds helps the complementary base pairs in DNA; guanine with cytosine and adenine with thymine to connect to one another. The hydrogen bonds between these complementary pairs helps keep the two strands of DNA helix together.
Answer:
Option D
Explanation:
All the plants and animals
1) The antibodies destroy the antigen (pathogen) which is then swallowed and digested by macrophages.
2) White blood cells can produce antitoxins which destroy the toxins that are otherwise known as poison.
