In parasitism, one organism harms another organism (the host). An example would be fleas living in cats/dogs; they feed on their blood.
Therefore the answer is A is harmed, and B is helped.
Answer:
I think it is c since "A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. Where possible, theories are tested under controlled conditions in an experiment. "
Adenine and thymine
cytosine to guanine
hope that helped
When a specimen is to be observed under the light microscope, scientists usually stain the specimens using different type of chemical stains depending on the type of specimen to be observed. Staining of specimen make the structures that are to be observed in the specimen very visible under the microscope, this make it easy for scientists to observe their structures.