8th Class Science Microorganisms : Friend and Foe Algae

      AIgae

They are the large group of simple plant like organisms, which contains chlorophyll and produce their food themselves. However, they are different from plants in many ways. They do not have stems, leaves and proper root system. Only some algae are unicellular and rests are multicellular. For example, diatoms and chlamydomonas are single cellular, where as blue green algae are multicellular. The blue green algae have the nitrogen fixing ability. It also known as cynobacteria. The other most common algae are red algae, brown algae, which are found in sea water.

                                      Algae

             Prions

The prion is a proteinaous infectious particle, which is generated by organisms, modified in spongiform encephalopathies. Prions form a group of microorganisms. It is composed by protein of 250 amino- acids. So far, no accurate structure or the information is available about the prions. It could be a sort of virus.

         Some algae are unicellular and some are multicellular. Some have chlorophyll, so they can manufacture their own food. Which one of the following is a multicellular algae?

(a) Diatoms

(b) Chlamydomonas

(c) Prions

(d) Cynobacteria

(e) None of these

Answer: (d)

Explanation

Only cynobacteria is the algae, which is multicellular and rest are unicellular.

           It is a protenious microorganism, which is composed of protein of 250-amino acid. Its structure is still not estimated and is a sort of virus. Identify the organism.

(a) Prions

(b) Lipase

(c) Plasmodium

(d) Rizophous

(e) None of these

Answer: (a)

Explanation

Prions is the algae having protenious composition and is similar to virus to some extent.