The neuron releases chemical messengers. Otherwise, there would be no 'signal transduction' in the postsynaptic cell. So, your answer is B.
I believe the correct answer from the choices listed above is the first option. A seamount is evidence of a convergent type of plate boundary. It<span> is an actively deforming region where two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide.</span>
Answer: Protozoa contaminate the water supply.
Some protozoa are parasites and cause diseases like malaria.
Protozoa have an important role in the food chain.
Protozoa are parasitic or free living single celled eukaryotic organisms. They are mostly found in water bodies.
Protozoa contaminate the water supply: Some of the protozoan species which are released from the human feces usually contaminate thee water, and causes waterborne infections in humans. Examples are Cryptosporium and Giardia. The infection occurs through drinking water or swallowing water from swimming pool.
Some protozoa are parasites and cause diseases like malaria: The Plasmodium is the genus belonging to the protozoan parasites. This malarial parasite is transmitted by female Anopheles mosquitoes to humans. The parasite multiply in the red blood cells causes symptoms like fever, anemia, flue, illness and may also cause coma and death.
Protozoa have an important role in the food chain: The protozoa species plays many roles in the food chain, they act as consumers, predators or prey, herbivores and decomposers. Their main function is to control the population of other species in the same habitat. They engulf small single celled bacteria, hence prevents excessive bacterial colonization act as predator. They also feed upon the algal species therefore, act as herbivores. They act as decomposers, as they feed upon the organic matter present in the bottom of the aquatic water body. They are the source of food for large worm and insect species.
