Which is the main light-absorbing pigment for photosynthesis?

The correct answer is- Chlorophyll a.

Chlorophyll is a green pigment that is found in the chloroplast of green plants and algae.

Chlorophyll a is considered as the primary pigment for photosynthesis as it is present in all photosynthetic eukaryotes.

In the first phase of photosynthesis (formation of food using carbon dioxide and water in the presence of sunlight), which is a light dependent phase, chlorophyll absorbs the solar energy and converts it into chemical energy in the form of ATP, and NADPH.

This energy is further utilized in the next phase (that is a light independent phase of photosynthesis) in formation of food (glucose) .

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.