AP BIOLOGY

Detailed explanation-1: -In 1911, Ernest Rutherford discovered that at the core of every atom is a nucleus. Atomic nuclei consist of electrically positive protons and electrically neutral neutrons. These are held together by the strongest known fundamental force, called the strong force.

Detailed explanation-2: -The nucleus (center) of the atom contains the protons (positively charged) and the neutrons (no charge).

Detailed explanation-3: -The nucleus is the positively charged centre of an atom and contains most of its mass. It is composed of protons, which have a positive charge, and neutrons, which have no charge.

Detailed explanation-4: -The Nucleolus-The nucleolus is a membrane-less organelle within the nucleus that manufactures ribosomes, the cell’s protein-producing structures. Through the microscope, the nucleolus looks like a large dark spot within the nucleus.