The correct option is (c).
Explanation
The nucleus is a double-membrane-bound organelle found in eukaryotic cells that houses the genetic material and controls cellular activities.
- Statement 1 is Incorrect: The nuclear membrane (nuclear envelope) is not impermeable. It is punctuated by minute openings called nuclear pores. These pores facilitate the transfer of materials, such as RNA and proteins, between the nucleus and the cytoplasm.
- Statement 2 is Correct: In a cell that is not dividing, genetic material exists as an entangled mass of thread-like structures known as chromatin. Distinct, rod-shaped structures called chromosomes become visible only when the cell enters the division phase.
- Statement 3 is Correct: Chromosomes are composed of DNA (Deoxyribonucleic Acid) and proteins (primarily histones). DNA contains the hereditary information necessary for cell function and reproduction, while proteins assist in the structural packaging of DNA.
Key Takeaway: The nucleus communicates with the cytoplasm through nuclear pores. Genetic material transitions from chromatin to distinct chromosomes (composed of DNA and protein) specifically during cell division.