Which one among the following cell organelles is semi-permeable?

The plasma membrane (also known as the cell membrane) is a semi-permeable or selectively permeable biological membrane [t1][t3]. It consists of a phospholipid bilayer with embedded proteins that regulate the movement of substances into and out of the cell [t5][t10]. This selective permeability allows essential nutrients to enter while preventing the entry of harmful substances and facilitating the exit of waste [c1][t8]. In contrast, the cell wall is a rigid outer layer found in plants and fungi that provides structural support and is generally fully permeable to water and small solutes [c3][t8]. While the nucleus is surrounded by a nuclear envelope, it contains large nuclear pores that allow the passage of macromolecules like mRNA and proteins, making it distinct from the semi-permeable nature of the plasma membrane [t4][t9]. Therefore, the plasma membrane is the most accurate answer for a semi-permeable structure.

Sources

1. [1] https://www.ncbi.nlm.nih.gov/books/NBK9928/
2. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 2: The Invisible Living World: Beyond Our Naked Eye > Activity 2.3: Let us investigate > p. 12
3. [3] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 2: The Invisible Living World: Beyond Our Naked Eye > Activity 2.3: Let us investigate > p. 13
4. [4] https://www.ncbi.nlm.nih.gov/books/NBK9927/