Eukaryotic cells are characterized by which features?

• A. They are unicellular organisms only
• B. They have membrane-bound organelles and DNA in a nucleus
• C. They lack DNA
• D. They do not have mitochondria

Answer: (B)

Eukaryotic cells are defined by compartmentalization: their DNA is housed in a nucleus, and the cell contains membrane-bound organelles that carry out specialized functions. The nucleus keeps genetic material separate from the cytoplasm, with DNA organized into linear chromosomes. Membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus allow distinct processes to occur in dedicated spaces. This organization distinguishes them from prokaryotic cells, which lack a true nucleus and most membrane-bound compartments and typically have DNA dispersed in the cytoplasm. So, the defining features are having membrane-bound organelles and DNA in a nucleus.