Questions: Multiple Choice Question Periplasm is a gel-like substance between the cell wall and the cell membrane. a gel-like substance external to the cell wall. a membrane that surrounds all bacterial cells.

The answer is the first one: a gel-like substance between the cell wall and the cell membrane.

Explanation for each option:

1. A gel-like substance between the cell wall and the cell membrane.

   • This is the correct answer. In Gram-negative bacteria, the periplasm is the space located between the inner cytoplasmic membrane and the outer membrane, containing a gel-like matrix. It is involved in various cellular processes, including nutrient transport and enzyme activity.

2. A gel-like substance external to the cell wall.

   • This is incorrect. The periplasm is not external to the cell wall; it is located between the cell wall and the cell membrane in Gram-negative bacteria.

3. A membrane that surrounds all bacterial cells.

   • This is incorrect. The periplasm is not a membrane, nor does it surround all bacterial cells. It is specific to Gram-negative bacteria and is a space containing a gel-like substance, not a membrane itself.

In summary, the periplasm is a gel-like substance found between the cell wall and the cell membrane in Gram-negative bacteria.