Answer: The nucleus.
Explanation: In an atom, there are two main parts, the nucleus and the electron cloud/electron shells. The protons and neutrons are located in the nucleus, and the electrons are located in the electron shells/cloud/whatever.
The flagella of the eukaryotes is composed of the doublet microtubules. The central bundle of these microtubules is known as the anoxeme. In an axoneme, a single pair of the singlet micortubules is surrounded by the nine doublet microtubules. When the plasma membrane of the flagellum is opened to expose the axoneme, and the radial spokes are broken, it will lead to the elongation of the axoneme,
The inflamitory response clogs up some whereever it is so the infection cannot spread.