Which of these is NOT a principle of the cell theory as it is currently understood?
A) Cells are the basic units of life
B) All living things are made of cells.
C) All cells are produced from existing cells.
D) Only cells containing mitochondria can reproduce.

D

Explanation:

It's false that "cells that contain mitochondria can reproduce". The function of mitochondria is to provide energy to the cell. Like prokaryotic cells do not contain mitochondria in it because it is a membrane-bound organelle. And prokaryotic cells can divide and produce new cells.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.