Final answer:
Chromosomes in eukaryotic cells are protected by the nuclear membrane, which encloses the nucleus, while ribosomes are involved in protein synthesis and are found in both eukaryotic and prokaryotic cells.
Step-by-step explanation:
In eukaryotic cells, chromosomes are protected by the nuclear membrane. This membrane encloses the nucleus, providing a barrier that segregates the chromosomal DNA from the cytoplasm. Prokaryotic cells, on the other hand, do not have a nuclear membrane; their DNA is located in a region called the nucleoid. The ribosomes are universal structures found in both prokaryotic and eukaryotic cells, responsible for protein synthesis, and are not involved in protecting chromosomes. While not directly protecting chromosomal DNA, ribosomes do play a crucial role in cell function by synthesizing proteins as instructed by the genetic material.
Furthermore, only eukaryotic cells have a membrane-bound nucleus. The presence of a nuclear membrane is one of the key features that distinguish eukaryotic cells from prokaryotic cells, along with several other membrane-bound organelles such as the endoplasmic reticulum, Golgi apparatus, mitochondria, and in plants, chloroplasts.