How would cellular respiration be impacted in the absence of photosynthesis? only aerobic respiration would take place. only anaerobic respiration would take place. fewer atp would be produced during cellular respiration. both reactants of cellular respiration would not be available.

The correct answer is 'Only anaerobic respiration would take place'.

Photosynthesis is a biological process through which plants synthesize their own food and oxygen is evolved as a byproduct. With the help of this oxygen living organisms are able to cellular respiration. Electron transport chain is a part of cellular respiration in which oxygen acts as ultimate electron acceptor. If oxygen is not available then a negative feedback loop will stop cellular respiration. But, in the absence of photosynthesis no oxygen will be evolved which means that cellular respiration will not occur. In such circumstances, only anaerobic respiration would take place and only those organisms will survive which are either obligate anaerobes or facultative anaerobes.

i think the answer is a.keratin is the pigment responsible for skin color.