Final answer:
Eukaryotic cells enclose their DNA within the nucleus, which is surrounded by a double membrane called the nuclear envelope. The nucleus contains most of the cell's genetic material in the form of chromosomes and includes the nucleolus, a site for ribosome synthesis.
Step-by-step explanation:
Eukaryotic cells have their DNA enclosed in the nucleus. The nucleus is a defining feature of eukaryotic cells, setting them apart from prokaryotic cells that lack a nucleus. Eukaryotic cells typically have their DNA organized into multiple linear chromosomes within the nucleus. This genetic material provides the instructions for the cell's functions and is essential for reproduction and heredity. The nucleus is enclosed by the nuclear envelope, a double membrane consisting of two lipid bilayers that regulate the transport of materials into and out of the nucleus through structures called nuclear pores. Within the nucleus, we also find the nucleolus, where the synthesis of ribosomes begins. The careful storage of DNA in the nucleus is crucial for maintaining the cell's genetic integrity and ensuring proper cellular function.