Video Transcript
The image provided shows a collection of cells that form the cardiac muscle of the heart. Billions of these cells work together to form heart tissue, which allows our hearts to beat continuously throughout our lives. Which principle of cell theory does this evidence support? (A) Cells are the basic functional unit of living organisms. (B) Cells are the smallest biological structure within an organism. (C) Cells cannot function individually and must work as a group. Or (D) all cells are made from preexisting cells.
Cell theory is one of the unifying theories in biology that was developed over hundreds of years by many different scientists. It has three principles or postulates. Let’s go through each one to see which best describes these cardiac muscle cells.
The first principle states that all living things are made of at least one cell. This is true for humans that are made of trillions of cells and single-celled organisms like bacteria. We’re all made of cells. However, this principle doesn’t really describe how billions of heart cells can work together to form heart tissue.
The second principle states that cells are the basic unit of life. We’re all made up of cells that work together to give us life, just like all these individual cardiac muscle cells can work together to form the heart. So answer choice (A) does seem correct. But let’s get to the final principle of cell theory and eliminate these other choices before settling on this as the final answer.
The third principle is that all cells come from preexisting cells. This principle describes more about how cells divide to form copies of themselves, which doesn’t describe these cardiac muscle cells working together to form heart tissue. So answer choice (D) is incorrect.
Answer choice (B) states that cells are the smallest biological structure within an organism. And this is incorrect because there are smaller structures within cells, like organelles like the mitochondrion. And the answer choice (C), which states cells cannot function individually and must work as a group, is also incorrect because cells can function individually, for example, single-celled organisms like bacteria.
Therefore, the observation that billions of cardiac muscle cells work together to form heart tissue is supported by the principle of cell theory that states that cells are the basic functional unit of living organisms.
