RRB NTPC Exam 2016: Science Made Simple (Inf.15) BACTERIA AND VIRUSES

RRB NTPC Exam 2016 General Science

RRB NTPC Exam 2016 will test you on your knowledge of Microbes like Bacteria and Viruses

RRB NTPC Exam 2016 #Daily Infographic on General Science (BIOLOGY)

RRB NTPC Exam 2016

Bacteria and viruses are very small organisms. Bacterial cells do not have a nucleus, and most have no organelles with membranes round them. However, they do have DNA, and their biochemistry is basically the same as other living things. A virus, on the other hand, is a tiny parasite which can infect living organisms.

 Some Bacteria are Useful

  • Bacteria help our bodies in several ways. They help with the digestion of food, and they help us to produce needed vitamins. Almost all bacteria are helpful to our health and well-being. Only a few types of bacteria cause disease. Many harmful organisms in our bodies are destroyed by bacteria.
  • Helpful bacteria help to purify water and they also are used to help breakdown the oil caused by oil spills.
  • Vaccines are created by using weakened bacteria.
  • Bacteria also help to make sourdough bread, yogurt, milk and cheese.
  • There are more bacterial cells in your body than there are human cells.

Dangers of a Virus

  • Viruses are about a thousand times smaller than bacteria and bacteria are much smaller than most human cells.
  • Scientists estimate that bacteria produce nearly half the oxygen found in the atmosphere.
  • Other than causing sore throat, cough, mild respiratory illness like runny nose without fever, a virus can also cause severe illness such as pneumonia.
  • A virus must have a host cell (bacteria, plant or animal) in which to live and make more viruses. Outside of a host cell, viruses cannot function.
  • A virus can enter our bodies through our nose, mouth or a break in the skin. Once they are inside the body, they must find a host cell to infect.

Differences between Bacteria and Virus

Bacteria Virus
Ribosomes Present Absent
Cell wall Peptidoglycan / Lipopolysaccharide No cell wall. Protein coat present instead.
Living attributes Living organism Opinions differ on whether viruses are a form of life or organic structures that interact with living organisms.
Introduction (from Wikipedia) Bacteria constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. A virus is a small infectious agent that replicates only inside the living cells of other organisms.
Number of cells Unicellular; one cell No cells; not living
Reproduction Fission- a form of asexual reproduction Invades a host cell and takes over the cell causing it to make copies of the viral DNA/RNA. Destroys the host cell releasing new viruses.
Structures DNA & RNA floating freely in cytoplasm. Has cell wall and cell membrane. DNA or RNA enclosed inside a coat of protein.
Treatment Antibiotics Vaccines prevent the spread and antiviral medications help to slow reproduction but can not stop it completely.
Enzymes Yes Yes, in some
Infection Localized Systemic
Benefits Some bacteria are beneficial (e.g. certain bacteria are required in the gut) Viruses are not beneficial. However, a particular virus may be able to destroy brain tumors (see references). Viruses can be useful in genetic engineering.
Size Larger (1000nm) Smaller (20 – 400nm)


TAKE THE QUIZ on Bacteria and Virus

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Helpful Links

How to Prepare General Science Section for RRB NTPC Exam

References: https://kidskonnect.com/science/bacteria-viruses/ , www.diffen.com 



  • Sahil

    Scored 1/5 🙁

    • Don’t worry. Revise the basic concepts in Biology and then give the quiz.