Question

Identify most mistaken (wrong) choice:

Select one:

a.

Bioremediation is the process by which microorganisms can be used to clean up toxic wastes.

b. Some bacteria can survive very low temperatures.

c.

Both prokaryotes and eukaryotes have ways of protecting themselves against free radicals.

d. Viruses can easily replicate in chemically defined media.

Answer 1

ANSWER:

Bioremediation is a process of waste management, in which microorganisms are used to remove or treat the pollutants of a polluted area. This area can be any water body like rivers, lakes etc. This method is useful in treating mainly toxic wastes because the microorganisms brak down these toxic substances into simpler forms. Hence, option 1 is CORRECT.

There are organisms which can survive at extreme conditions, may be hot or cold. These are known as Extremophiles. The extremophiles which survive in extremely low temperatures are called psychrophiles or cryophiles. Their survival temperature ranges from -10°C to -20°C. These organisms include some kind if bacterias, fungi, lichens etc. Psychrophilic bacteria include Psychrobacter, polaromonas arthrobacter etc. Hence, option 2 is CORRECT.

Both eukaryotes and prokaryotes can protect themselves from free radicals. Free radicals are highly reactive molecules which destroys the cells. Eukaryotic cells have peroxisomes which prevents them from free radicals. Also, microorganisms have developed a mechanism to fight against free radicals. Hence, option 3 is CORRECT.

Viruses cannot survive outside its specific host. Hence it is not easy to replicate a virus outside of cells in chemically defined media. Some insect virus can replicate in a chemically defined media, but it is not easy to do so. Hence, option 4 is INCORRECT.