Answer:
The correct answer is - hydrogen bond.
Explanation:
Hydrogen bonding is very essential for life on earth. DNA has a double-helix structure that means it has two distinct strands in its structure and hydrogen bonds hold together the nitrogen base pairs in the middle. In absence of hydrogen bonds, DNA would have to exist as a different structure. The principal force or bonds between those two strands are Hydrogen bonds between the nitrogen bases. Adenine always makes a hydrogen bond with Thymine whereas Guanine always binds with cytosine.
Thus, the correct answer is - hydrogen bond.
The Nucleus shows the different functions
Living things consists of the organisms like the plants, animals, fungi, protozoa and bacteria. These animals vary in the complexity of the body and have different number of cells in their body. Organisms like the plants and animals are made up of several different kinds of cells. These organisms are called multi-cellular organisms. On the other hand, organisms like the baker's yeast (a fungi) and a plethora of bacteria are single celled organisms. They are called unicellular organisms. Hence we can say that the living things are made up of at least one cell.