Which term applies to the fact that the protozoan that causes malaria is very harmful and often kills its host? a. commensalism b. parasitism c. mutualism d. symbolism

The correct term is parasitism. That is option B.

Malaria is a type of disease that is usually caused by the bite of a female anopheles mosquito.

The insect transmits protozoan called plasmodium, which completes its cycle in the living human host with the display of the following symptoms:

Since the protozoan that causes malaria is very harmful and often kills its host, it has a parasitic feeding relationship with the host.

Parasitism is a mode of nutrition where an organism lives on or in another organism known as host, causing harm or death to the host.

Therefore the correct term is parasitism.

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the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.