Tag: bacteria - introduction, shape and structure

Superbugs is a term used to describe strains of bacteria that are resistant to the majority of antibiotics commonly used today. These resistant bacteria can cause pneumonia, urinary tract infections, skin infections and many other diseases that are difficult to treat and may be fatal.

An anaerobic organism or anaerobic bacteria is any organism that does not require oxygen for growth. It may react negatively or even die if oxygen is present. Mitochondria, Golgi body and ER are organelles of eukaryotic organisms. Since anaerobic bacteria is prokaryotic, they are absent in anaerobic bacteria.

Denitrifying bacteria convert nitrates in the soil to free atmospheric nitrogen, nitrogen-fixing bacteria are heterotrophs.

Viruses can be made into a crystalline form. TMV became the first virus to be crystallized in 1935. One crystal of viruses consists of thousands of viruses. The crystallization of viruses was first done by Stanley. Algae, Amoeba and Sperm cannot be crystallised.

The correct answer is C.

All viruses live inside host cell, they cannot function outside the cell. Unlike bacteria which rarely live in the host cell. Therefore, (c) is the correct answer.

Virus is the microorganisms which have properties of living and non-living both. They have a specific structure which consists of head and tail. Head is composed of several protein units known as capsomeres which enclose the genetic material made up of RNA or DNA. They have a lipid envelope derived from the host cell membrane which lies outside the capsomere. They occur in crystalline form outside the body of the host but as it enters the host cell it injects its genetic material which replicates vigorously. The replicated materials are further packed in the new protein coat formed using host protein and is thrown out by the lysis of cell membrane.

There are $5$ codes of nomenclatures:- 

A virus is a small infectious agent, that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea. All viruses are obligate parasites; i.e., they lack metabolic machinery of their own to generate energy or to synthesize proteins, so they depend on host cells to carry out these vital functions. Thus, option C is correct.
Viruses do not possess their own metabolic system. So, depends on host machinery. Thus, option A is wrong.
All viruses contains either DNA or RNA as genetic material but, not both. Thus, option B is wrong.
The protein coat of virus is called as capsid. Thus, option D is wrong.