What are two types of materials or observations that would necessitate the use of the stereoscopic microscope?

What organelles are visible with the electron microscope but not with the light microscope?

(we've been studying single celled organisms and organelles).

To answer the first question, two types of materials or observations that would necessitate the use of a stereoscopic microscope are:

1. Three-dimensional objects: The stereoscopic microscope, also known as a dissecting microscope, provides a three-dimensional view of the specimen. It is particularly useful when studying relatively large objects that require depth perception, such as rocks, minerals, insects, or plants.

2. Opacity or transparency: The stereoscopic microscope is highly beneficial when observing materials that are either too opaque or too translucent for a compound light microscope. For instance, studying the intricate structures of fossils or examining the internal organs of an organism may require the use of a stereoscopic microscope.

Moving on to the second question, the organelles that are visible with an electron microscope but not with a light microscope are:

1. Ribosomes: While ribosomes can be visualized to some extent with a light microscope, their detailed structure is only visible with an electron microscope. Electron microscopy allows for a higher level of magnification and resolution, revealing the ribosomes' intricate subunits and their arrangement within the cell.

2. Endoplasmic reticulum (ER): The ER is a complex network of membrane structures involved in protein synthesis and lipid metabolism. Its detailed structure, with its interconnected tubules and flattened cisternae, can be seen more clearly with an electron microscope. Light microscopes do not have the resolution required to visualize the ER in such detail.

3. Golgi apparatus: The Golgi apparatus is involved in processing and modifying proteins produced by the cell. The flattened stacks of membranous compartments that form the Golgi apparatus are best viewed with an electron microscope, as their detailed structure cannot be fully appreciated with a light microscope.

It is worth noting that the electron microscope provides a much higher magnification and resolution compared to the light microscope, allowing for the visualization of smaller organelles and more intricate cellular structures.