Question

1. what structural feature of the cell membrane allows it to be selectively permeable? a. the double helix structure of dna. b. the fluid inside the nucleus. c. the presence of channels and pores. d. its rigid outer layer.

Explanation:

The cell - membrane's selective permeability is due to the presence of channels and pores that control the movement of substances in and out of the cell. The double - helix structure of DNA is related to genetic information storage, the fluid inside the nucleus is nucleoplasm and not related to cell - membrane permeability, and a rigid outer layer is not a characteristic that makes the cell membrane selectively permeable.

Answer:

C. The presence of channels and pores