Question

Spirochetes are
A. A class of viruses
B. Myxobacteria
C. Spiral- shaped bacteria
D. Rickettsia

Answer 1

Microorganisms such as bacteria, viruses and fungi exist in a variety of shapes. The specific shapes can help these organisms in being adapted to certain conditions, as well as in attaching to the host surface.

Complete answer: A spirochete is a bacteria that is spirally shaped. These organisms have very high motility. They are very small, and can only be visualized with the help of a dark field microscopy. Due to their characteristic shape, they have a motility pattern similar to that of a corkscrew. It is aided by the presence of flagella. They are mainly parasitic and are involved in causing many infectious diseases such as syphilis (Treponema pallidum).
A. Viruses are the most primitive living cells. They exist extensively as obligate parasites in higher organisms. These cells do not have an independent existence outside the host cells. They have an outer protein coat, that encloses the genetic material, which can be either DNA or RNA.
B. Myxobacteria refers to a bacterial group which lives in the soil. These organisms feed on the organic materials present in the soil which are insoluble. They are primarily involved and commercialized in producing chemicals such as antibiotics.
D. Rickettsia is a class of non-motile bacteria. They do not produce spores, and also are gram-negative. These organisms also survive as parasites. One of the major diseases caused by these organisms is Spotted fever. Thus it is not the appropriate option.
Therefore, the correct answer is option C.

Note: The infections caused by Spirochetes can be treated using a wide spectrum of antibiotics. The widely used antibiotics are Penicillin- G, doxycycline, tetracycline and Erythromycin.