Question

Light microscopes are not powerful enough to view most organelles found within cells, however, what structure(s)/organelle(s)of the eukaryotic cells were visible? Why do you believe this was the case?

Answer 1

Due to their size and the limited resolution of light microscopy, most cellular organelles are not visible or their detailed structure can't be studied in regular stained tissue sections. The major exception is the cell nucleus of all nucleated cells.

From "Cell Biology for Histologists"

Answer 2

Light microscopes are capable of resolving structures and organelles in eukaryotic cells that are larger in size, such as the nucleus, cytoplasm, cell membrane, and mitochondria. These structures are visible because they are relatively larger in size and have a higher refractive index compared to other cellular components, which makes them easier to distinguish using light microscopy.

The nucleus is one of the most prominent structures visible under light microscopy, as it is typically the largest organelle in a eukaryotic cell and contains genetic material that is responsible for regulating cellular activities. The cytoplasm, which includes the cytosol and various organelles such as mitochondria, lysosomes, and peroxisomes, is also visible as a distinct region within the cell. Additionally, the cell membrane, which encloses the cell and regulates the exchange of materials between the cell and its environment, can be seen as a thin, translucent layer.

However, many organelles within eukaryotic cells, such as the endoplasmic reticulum, Golgi apparatus, and various vesicles and microfilaments, are too small to be resolved using light microscopy alone. To visualize these smaller organelles, more powerful microscopy techniques such as electron microscopy are needed.