Aspecies has 6 chromosome pairs in each diploid cell. how many genetically unique gametes could be produced from sexual reproduction in this species, accounting only for independent assortment?

There are 6 pairs of chromosomes that divide by independent assortment. Each pair consists of 2 chromosomes so it could be divided by 2 ways. So, if there is 6 pairs, the possible ways would be:
2*2*2*2*2*2= 2^6= 64 possible ways

The answer is joseph is observing the colour of the reaction mixture to see whether proteins are present in the given solution.