Question

all of the organs of the respiratory system are built of... cells, which are made of tissues. blood and skin tissues. tissues, which are made of cells. blood and skin cells.

Explanation:

To solve this, we recall the biological organization: cells form tissues, tissues form organs. Organs of the respiratory system (like lungs, trachea) are made of tissues, and tissues are made of cells. Let's analyze each option:

• First option: Cells are made of molecules, tissues are made of cells (reverse), so wrong.
• Second option: Blood and skin tissues are not the main components of all respiratory organs, wrong.
• Third option: Tissues (made of cells) make up organs, this follows the biological hierarchy.
• Fourth option: Blood and skin cells are not the building blocks of all respiratory organs, wrong.

Answer:

C. tissues, which are made of cells.