Final answer:
Eukaryotes are characterized by having a nucleus, membrane-bound organelles, and an endoplasmic reticulum. They are distinct from prokaryotes, which do not have these features.
Step-by-step explanation:
The characteristics of eukaryotes include the presence of a nucleus, organelles, and an endoplasmic reticulum. Therefore, the correct answers are:
- A nucleus is present (a).
- Organelles are present in the cytoplasm, such as mitochondria, the endoplasmic reticulum (ER), Golgi apparatus, lysosomes, and peroxisomes (c).
- The endoplasmic reticulum is one of the many membrane-bound organelles found in eukaryotic cells performing specialized functions (e).
Eukaryotic cells are distinct from prokaryotic cells, which lack a nucleus and lack membrane-bound organelles. Eukaryotes may have a cell wall, but it does not contain peptidoglycan, which is found in the cell walls of many bacteria, a group of prokaryotes.