What would happen if photosynthesis on earth stopped? all plants and animals would die due to the absence of oxygen and carbohydrates (glucose) for respiration. all plants would die as they wouldn't be able to produce carbohydrates, while animals would survive because they don't carry out photosynthesis. all plants and animals would survive as they can carry out respiration, despite the absence of photosynthesis. 

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.