What helix shaped structure tells the cell when to grow and what to do?

Ans.

The helical-shaped structure that controls the activities of cells is known as DNA (deoxyribonucleic acid). The structure of DNA resembles a double-helical structure, which comprises two single stranded DNA molecules, joined together in anti-parallel manner with the help of hydrogen bonds between nitrogen bases.

It controls the activities of a cell, such as growth and division by expressing specific genes for code proteins that play role in specific activities.

Thus, the correct answer is 'deoxyribonucleic acid.'

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."