Which biomolecule is fundamental to the structure and function of biological membrane, such as cell membrane?

Nucleic acid certain protein cell membranes certain carbohydrates

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?

Staining is an important way to improve what aspects of microscopy?