Question

Identity the facultative parasite from the below given.
A. Enterobius vermicularis
B. Mycobacterium tuberculosis
C. Taenia solium
D. Trichomonas hominis

Answer 1

Hint: Facultative parasites are organisms that do not completely rely on the host for nutrition and completion of their life cycles. The word facultative means a tendency to change the mode of living and parasites are organisms that rely on the host completely for survival.

Complete answer: Facultative parasites are organisms that can have a tendency to resort to parasitic activity. These organisms do not rely on any host for completion of their life cycle. Facultative parasitism occurs in many species of fungi like members of the genus Armillaria.
Now, let us go through the enlisted options given in the question.
In option A, Enterobius vermicularis is mentioned. It is widely known as a human pinworm. It is a roundworm. It caused the pinworm infection. The entire life cycle of this organism has relied on the human intestine. The eggs hatch and adults are formed. They mate in the colon after which the male dies. After laying the eggs females die. The cycle lasts 4-8 weeks.
In option B, Mycobacterium tuberculosis is mentioned. It is a pathogenic bacterium that causes tuberculosis. The bacterium is inhaled and then it travels to the macrophages of the human. The bacteria then multiply and cause the disease.
In option C, Taenia solium is mentioned. It is also known as the pork tapeworm. It is a type of tapeworm that has humans as its definitive host and pigs as a secondary host. It belongs to the phylum Platyhelminthes and class cestoda. Their life cycle includes hatching from the egg, residing in the host, here the intestine for nutrition, and leaves the body through the anus.
In option D, Trichomonas hominis is mentioned. It is a protozoan that is taken by humans orally. They reside in the oral cavity, urinal cavity, or intestine depending upon the species.

So, the correct option is option B.

Note: Mycobacterium tuberculosis is nonmotile, rod-shaped bacterium. They are found most often in dry and oily locales. Mycobacterium tuberculosis is an obligate aerobe. That is why they are always found in the well-aerated upper lobes of the lungs. The bacterium has a slow generation time that is 15-20 hours. Mycobacterium species is related to the genus Nocardia.