The answer is aerobic. Although cellular respiration can happen anaerobically and aerobically, the question states that it requires oxygen. Therefore, it is aerobic.
The rate mainly effects the size of the crystals in the rock forming
The right option is; dark-field microscope
A light microscope that makes the specimen appear light on a dark background is called a dark field microscope.
Dark field microscopes are light microscopes that are used in different ways to clearly view various specimens that are unstained, transparent, and hard to see using a light field unit. Dark field microscopes are very effective because they show the details of unstained and live samples. It is also very simple to use, and inexpensive to set up.
Its b. Ecosystem
Population is the number of a species in an area, it has nothing to do with physical characteristics.
Abiotic is just an adjective meaning not alive
Competition is just the interactions between organisms in the struggle for food, water, space, mates, and many other things again not physical characteristics