1. Simple optical microscope. One lens.
Disadvantage: Only Van Leeuwenhoek made them, and he's dead.
Advantage: Worked pretty well. With them, Van Leeuwenhoek discovered protozoa and bacteria.
2. Compound optical microscope. Has both an ocular and objective lens.
Disadvantage: limited resolution. Can resolve bacteria, but not smaller things like viruses.
Advantage: can be used with live specimens (using phase contrast or polarized or other special illumination).
3. Binocular dissecting microscope (optic). Has a pair of ocular and objective lenses, and supposedly presents a "3D" view of the specimen to the viewer (I was never able to see in 3D using these darn things).
Disadvantage: Limited magnification
Advantage: Can be used to perform surgery on small but not microscopic specimens, such as fruit flies. Is used in "microsurgery" in hospitals too.
Hope this helps buddy!
The answer is 1, either ( AA, Aa, or aa ) .
Answer:
False.
Explanation:
I am almost entirely sure that DNA testing had not been discovered at this time, but regardless of whether that is true, the very first criminal case that DNA testing was used in occurred in 1985. So no, it was not used commonly in the 20's.
The source of inorganic fertilizer is from plant or animal based materials that are either a byproduct or end product of naturally occurring processes like leaves, and compost.
The answer is Speciation cannot occur in the absence of mutation. Speciation cannot occur in the absence of natural selection
