All living cells possess a plasma membrane and cytoplasm.
a plasma membrane and a nucleus a nucleus and chloroplasts.
plastids and vacuoles.
a cell wall and cytoplasm.
The correct answer and explanation is:
The correct answer is: a plasma membrane and cytoplasm.
All living cells, whether prokaryotic or eukaryotic, have two fundamental components: the plasma membrane and cytoplasm.
- Plasma Membrane: This is the outer boundary of the cell. It acts as a selective barrier, regulating the entry and exit of substances. It also plays a critical role in communication with the environment and other cells. The plasma membrane is made up of a phospholipid bilayer with embedded proteins, which allows it to be fluid and flexible, adapting to the cell’s needs. This membrane controls the movement of ions, nutrients, gases, and waste products.
- Cytoplasm: The cytoplasm is the semi-fluid substance that fills the interior of the cell. It is composed of cytosol, a gel-like substance, and contains various organelles in eukaryotic cells or the nucleoid region in prokaryotes. The cytoplasm is where most of the cell’s metabolic processes occur, including protein synthesis, energy production, and cell division. It provides a medium for enzymes and other molecules to interact and function within the cell.
In contrast, the other options mentioned:
- A plasma membrane and a nucleus: This is true for eukaryotic cells, which have a nucleus, but not all living cells have a nucleus (e.g., prokaryotic cells like bacteria).
- A nucleus and chloroplasts: Chloroplasts are present only in plant cells and some algae, so this does not apply to all living cells.
- Plastids and vacuoles: These organelles are specific to plant cells and some protists, not all living cells.
- A cell wall and cytoplasm: While plant, fungal, and bacterial cells have cell walls, not all living cells possess a cell wall (e.g., animal cells lack a cell wall).
Thus, the plasma membrane and cytoplasm are the universal features present in all living cells.