Question

Identify the algae responsible for biological activity called bioluminescence?
A. Chlorella
B. Spirogyra
C. Cyclotella
D. Noctiluca

Answer 1

The term bioluminescence means the phenomenon by which the organisms tend to emit light on their own and they also tend to produce light on their own. Bioluminescence is supposed to occur in the living organism only. Light can also be produced with the help of chemical means and it is known as chemiluminescence and the former one is the part of the latter one.

Complete answer:
The bioluminescence is achieved by the organisms which are living in marine environments and the freshwater and terrestrial organisms do not produce any kind of light.
Now if we look at the given option we see chlorella and spirogyra first in the list. If we remember the chapter of classification, then we will know that these two algaes are terrestrial ones and they are also autotrophs because the have chloroplasts inside them and as we discussed above the criteria for an organism to be a bioluminescent one is marine habitat so these two can be ruled out from our choice list.
The next option in the list is of the cyclotella, now this algae is water living algae but there is a catch. Most of the cyclotella have been found to live in the freshwater environment and only a very rare species live in the marine water. Since this is a freshwater algae so they also cannot emit light on their own. So our last option might be correct according to our criteria.
Now the last option is of Noctiluca which is a marine water organism and as the name itself is indicating about its character, Nocti meaning night and luca meaning shine and if we combine the terms we get night shining algae.

Hence, the correct answer is option (D).

Additional information:
The bioluminescence feature of the algae is displayed by the ones which generally have the habitat of water and other algaes do not tend to show this feature of emitting light.

Note: chlorella and spirogyra are out of the options because of the presence of chlorophyll so they will be inactive during night time and Cyclotella is a single celled algae which cannot emit light alone.