Florida Biology EOC Practice Test

According to cell theory, which of the following is true?

1. All living things are made of cells

2. Proteins are the basic unit of life

3. Enzymes control all cell activities

4. Only animals are composed of cells

The correct answer is: All living things are made of cells

The statement that all living things are made of cells is a fundamental principle of cell theory, which is a cornerstone of biological science. Cell theory establishes that cells are the smallest units of life and that all living organisms, from the simplest bacteria to complex multicellular organisms like plants and animals, are composed of one or more cells. This unifying concept underscores the biological connection between all forms of life on Earth. The other statements do not align with the principles established by cell theory. While proteins and enzymes play critical roles in cellular functions, they are not considered the basic unit of life; that role is attributed to the cell itself. Additionally, the assertion that only animals are composed of cells is incorrect, as it disregards the fact that plants, fungi, and many microorganisms are also entirely made up of cells. Thus, the assertion that all living things are made of cells accurately reflects the essence of cell theory.