Answer:
Most biomolecules are organic compounds, and just four elements—oxygen, carbon, hydrogen, and nitrogen—make up 96% of the human body's mass. But many other elements, such as the various biometals, are present in small amounts. Sometimes polymers are also known as macromolecules or large-sized molecules. Usually, polymers are organic (but not necessarily). A monomer is a molecule that is able to bond in long chains.
Explanation:
Understand?
Answer:
The cilia is one of the things that act defensively in the respiratory system.
Explanation:
It propels a mucus-like liquid that covers the airway which traps pathogens (potentially infectious microorganisms) and other particles, preventing them from reaching the lungs.
Answer:
D.
Explanation: Ecology: relation of organisms with one another or their surroundings.