Select the combination of option that will correctly complete the below statements.
I. A typical eukaryotic cell has membrane bound distinct structures namely,(P).
II. All the prokaryotes are known to have a layer of cell wall around its cell membrane except (Q)
III. A special membranous structure found in a bacteria is (R) which is formed by the extensions of the plasma membrane of the cell.
IV. (S) are thin filamentous extensions from cell wall that helps the bacterial cell with motility.

Options

A. P - organ , Q - mycoplasma , R - peroxisome , S - cilia
B. P - organelle , Q - eubacteria , R - mesosome , S - flagella
C. P - organelle , Q - mycoplasma , R - mesosome , S - flagella
D. P - vesicle , Q - eubacteria , R - peroxisome , S - flagella

Answer

To solve the question, we need to fill in the blanks (P, Q, R, S) in the given statements with the correct terms related to eukaryotic and prokaryotic cells.

### Step-by-Step Solution:

**I. A typical eukaryotic cell has membrane-bound distinct structures namely, (P).**
- In eukaryotic cells, the distinct structures that are membrane-bound are called **organelles**. These include the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, etc.
- Therefore, (P) = **organelles**.

**II. All the prokaryotes are known to have a layer of cell wall around its cell membrane except (Q).**
- Most prokaryotes have a cell wall, but there is an exception. The prokaryote that lacks a cell wall is **Mycoplasma**.
- Therefore, (Q) = **Mycoplasma**.

**III. A special membranous structure found in a bacteria is (R) which is formed by the extensions of the plasma membrane of the cell.**
- The special membranous structure in bacteria that is formed by the invagination of the plasma membrane is called a **mesosome**.
- Therefore, (R) = **mesosome**.

**IV. (S) are thin filamentous extensions from the cell wall that helps the bacterial cell with motility.**
- The structures that provide motility to bacteria are called **flagella**. These are long, whip-like appendages that enable movement.
- Therefore, (S) = **flagella**.

### Final Answers:
- (P) = organelles
- (Q) = Mycoplasma
- (R) = mesosome
- (S) = flagella