Explanation:
Primary succession, type of ecological succession (the evolution of a biological community’s ecological structure) in which plants and animals first colonize a barren, lifeless habitat. Species that arrive first in the newly created environment are called pioneer species, and through their interactions they build a simple initial biological community. This community becomes more complex as new species arrive. Primary succession is distinguished from secondary succession, which is the recovery of an existing biological community after a disturbance sets back the community’s ecological structure to an earlier stage.
The type of microscope that <span>can produce three-dimensional images of a cell’s surface is the electron-scanning microscope. In this type, beam of high-energy electrons is focused to project the correct projection of the cells. The projection of the cells are made up of signals of the surface.</span>
The correct answer is A. Experimental group
Explanation:
In experiments, the experimental group refers to the group of subjects that receives special treatment or in which the scientist or researcher intervenes. This is the opposite of a control group that does not receive treatment and therefore, it is used as a reference to measure the effect of the treatment.
This implies, in the experiment presented Group A is the control group as they do not have special treatment because they sleep normally and Group B is the experimental group as the researcher modifies their sleep time and reduces it two hours which means in this group there is a treatment or intervention.
Limiting factors control the size and growth of an organism’s population.
