The color of red snow is due to A. Chlamydomonas sowiae B. Chlamydomonas nivalis C. Both A and B D. None of the above
Hint: Red snow or pink snow is found at certain places on Earth. The color of the snow is not red, but actually it appears red due to the presence of an algae species belonging to the genus Chlamydomonas.
Complete answer: Red snow is a phenomenon caused by a species of green algae called Chlamydomonas nivalis. These species contain a secondary or accessory pigment – the red carotenoid pigment. It is also called ‘astaxanthin’. These algae are cryophilic i.e. it loves the cold atmosphere. Being an accessory pigment the astaxanthin provides protection to the chloroplast from the UV rays. During winters in certain areas, these algae switch to dormancy and upon onset of spring, their germination is stimulated. Upon germination, small flagellates have released that move towards the snow surface.
So, the correct option is B. Chlamydomonas nivalis.
Note: The red snow is also called watermelon snow due to its pink color. It can be seen in the alpine and some coastal Polar Regions of the World during the summer season. Making snowballs, stepping on the snow, or compressing it somehow makes it look reddish/pink colored.