Which structure in the cell contains chromosomes and nucleoplasm?

The correct answer is the nucleus, which is the structure within the cell that houses chromosomes and nucleoplasm. Chromosomes, which are made up of DNA, contain the genetic information necessary for the cell's function and replication. The nucleoplasm is a viscous, gel-like substance found within the nucleus that surrounds the chromosomes and is involved in various activities, including the synthesis of RNA and ribonucleoproteins.

The nucleus serves as the control center of the cell, facilitating processes such as gene expression and replication. Its presence is vital for maintaining the integrity of genetic material and coordinating the cell's activities. In contrast, structures like the cytoplasm and cell membrane do not contain chromosomes, and muscle tissue is a type of cellular organization rather than a part within a cell. Understanding the function of the nucleus helps clarify its role in cellular biology and genetics.