Penicillin has inhibitory effect over bacteria by

Options

A. Destruction of nucleus
B. Inhibition of cell wall synthesis
C. Stopping entrance of antibody
D. None of the above.

Answer

### Step-by-Step Solution:

1. **Understanding Penicillin**: Penicillin is an antibiotic that is commonly used to treat bacterial infections. It is known for its effectiveness against a variety of bacteria.

2. **Mechanism of Action**: The primary mechanism by which penicillin exerts its effects is through the inhibition of bacterial cell wall synthesis. This is crucial because the cell wall provides structural integrity to the bacteria.

3. **Cell Wall Composition**: Most bacteria have a cell wall composed of peptidoglycan. Penicillin interferes with the enzymes that are responsible for the synthesis of this peptidoglycan layer.

4. **Bacterial Autolysis**: In addition to inhibiting cell wall synthesis, penicillin can induce a bacterial autolytic effect. This means that the bacteria may begin to break down their own cell walls, leading to cell lysis (death).

5. **Conclusion**: Therefore, the correct answer to the question is that penicillin has an inhibitory effect over bacteria by "inhibition of cell wall synthesis".

### Final Answer:
Penicillin has an inhibitory effect over bacteria by **inhibition of cell wall synthesis**.

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