What are the basic structural and functional units of the body and all living organisms?

What are the basic structural and functional units of the body and all living organisms?

• A. Cells
• B. Nucleus
• C. Organs
• D. Tissues

Answer: (A)

Cells are the basic structural and functional units of the body and all living organisms. They are the smallest units capable of carrying out life processes such as metabolism, growth, and reproduction. In multicellular organisms, cells specialize and organize into tissues, which form organs and then organ systems. The nucleus, while a key component inside many cells that stores genetic material and directs activities, is not the fundamental unit itself. Tissues and organs represent higher levels of organization built from cells, not the basic unit. Some organisms are unicellular, meaning a single cell performs all life processes. This idea is encapsulated by cell theory: all living things are made of cells, and new cells arise from existing cells.

Cells are the basic structural and functional units of the body and all living organisms. They are the smallest units capable of carrying out life processes such as metabolism, growth, and reproduction. In multicellular organisms, cells specialize and organize into tissues, which form organs and then organ systems. The nucleus, while a key component inside many cells that stores genetic material and directs activities, is not the fundamental unit itself. Tissues and organs represent higher levels of organization built from cells, not the basic unit. Some organisms are unicellular, meaning a single cell performs all life processes. This idea is encapsulated by cell theory: all living things are made of cells, and new cells arise from existing cells.