World population stops growing
Answer:
lvl 2 - Molecules consist of atoms
lvl 3 - Cells consist of molecules
lvl 4 - Organisms consist of cells
lvl 5 - Populations consist of organisms
lvl 6 - Communities consist of populations
lvl 7 - Ecosystems consist of communities interacting with their environment
lvl 8 - The biosphere consists of all ecosystems on Earth
Explanation:
Cell wall because their has to be something protecting it.
The activity of some enzymes requires vitamins. This is because vitamin derivatives contribute to the biochemical mechanisms of these enzymes. These vitamin derivatives belong to a class of molecules known as cofactors, which are organic molecules (called coenzymes) or metallic ions, that assist in the catalytic activity of an enzyme.
