Which of the following is stated in the cell theory?

• A. Cells are connected by tight junctions to form tissues.
• B. All living organisms are composed of one or more cells.
• C. Desmosomes provide structural support to plant cells.
• D. Cell junctions are responsible for cell communication.

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the cell theory, which is a fundamental principle in biology. It consists of three main statements: (1) All living organisms are composed of one or more cells, (2) The cell is the basic unit of structure and function in living organisms, and (3) All cells arise from pre-existing cells.
2. Step 2: Analyze the options provided in the problem. The first option, 'Cells are connected by tight junctions to form tissues,' refers to a specific cellular structure and function, not a principle of the cell theory.
3. Step 3: Evaluate the second option, 'All living organisms are composed of one or more cells.' This directly aligns with the first statement of the cell theory and is therefore correct.
4. Step 4: Examine the third option, 'Desmosomes provide structural support to plant cells.' Desmosomes are cellular structures involved in adhesion, but this is unrelated to the cell theory.
5. Step 5: Assess the fourth option, 'Cell junctions are responsible for cell communication.' While cell junctions play a role in communication, this is not part of the cell theory. Thus, the correct answer is the second option.