Answer:
Hydrogen bonds make water molecules spread out when they freeze. This makes ice less dense than water and allows ice to float. If ice did not float then oceans and lakes would freeze from the bottom up, killing marine life by trapping organisms in the ice. When ice floats, it insulates the water below, keeping it at around 4 degrees C or 40F, which does not freeze and allows fish to survive the winter.
Explanation:
The question is incomplete. The complete question is attached below.
Answer:
1. DNA is the polymer of deoxyribonucleotides that contain the nitrogenous base, pentose sugar and phosphate group. The phosphate is attached with the 3 C position of the deoxyribose sugar. This leads to teh formation of phosphodiester bond.
2. The DNA backbone consists of phosphate and sugar. The nitrogenous bases are inserted inside the DNA molecule. These nitrogenous bases are linked together by the hydrogen bonds.
3. The adenine binds requires two hydrogen bonds to bind with thymine. This provide complementary nature to the DNA molecule. Uracil is present instead of thymine in RNA .
4. The guanine binds requires three hydrogen bonds to bind with cytosine. More amount of energy is required to break their bonds.