Final answer:
Under the microscope, an anther's cross section includes microsporangia or pollen sacs, which contain microspore mother cells that develop into pollen grains. The tapetum within facilitates this growth, and mature pollen is released when the sac walls open. Electron microscopes offer a more detailed view of these structures than light microscopes.
Step-by-step explanation:
The cross section of an anther under the microscope looks like it contains several important features. During the two developmental stages, immature anthers contain four microsporangia, or pollen sacs, which house hundreds of microspore mother cells. These cells eventually give rise to pollen grains. The internal tissue called the tapetum supports the growth and maturation of these pollen grains. As the pollen matures, the walls of the pollen sac split open, allowing for the release of the male gametophytes (pollen). If you view this process under a scanning electron microscope, the details of pollen sacs and the structural features of pollen at the microscopic level become much more apparent.
Looking further into male gametophyte development, within the anther's microsporangia, the microspores undergo division to form the male gametophyte or the pollen grains. These pollen grains carry the male genetic material necessary for the fertilization of the female gametophyte.
Electron microscopes provide an enhanced view that shows much more detail compared to a light microscope. For example, bean-shaped grains of pollen can be observed at higher magnification and resolution thanks to the electron microscope's ability to produce images with much shorter wavelengths than those of visible light.