This simple bacteria cell has the same structure as more complex cells. It controls what comes in to and leaves the cell and also maintains homeostasis. It is the

A) capsule.
B) cytoplasm.
C) membrane.
D) wall.**

A cell wall occurs in plants.

The correct answer is C) membrane.

To determine the answer, let's break down the question and the options provided.

The question states that this simple bacteria cell has the same structure as more complex cells. We are looking for a structure that performs multiple functions like controlling what comes in and out of the cell and maintains homeostasis.

Let's evaluate the options:
A) Capsule: The capsule is a protective layer found outside the cell wall in some bacteria, but it does not control what enters or leaves the cell.
B) Cytoplasm: The cytoplasm refers to the fluid inside the cell that contains various organelles and molecules. While it is important for cellular processes, it does not specifically control what enters or exits the cell.
C) Membrane: The cell membrane, also known as the plasma membrane, is a thin, flexible barrier that surrounds the cell. It is involved in controlling the movement of substances in and out of the cell, as well as maintaining homeostasis by regulating the exchange of essential molecules and nutrients.
D) Wall: The cell wall provides structural support and protection to the cell, but it does not directly control the movement of substances.

Based on the above analysis, the correct answer is C) membrane.