The ph indicator bromothymol blue turns yellow when co2 gas is added to a solution and blue when co2 is removed from a solution. an experiment will test how the intensity of light affects the rate of photosynthesis in algae. which of these should be a control for this experiment? a. algae that are placed in a yellow solution and keep in the direct sunlight. b. algae that are placed in a blue solution and kept in direct sunlight. c. algae that are placed in a yellow solution and kept in the dark. d. algae that are placed in a blue solution and kept in the dark.

1. true.2. true.3. true.4. false.5. true.the concept of darwin's theory of evolution involves the idea that there are limited resources in a given living environment and that the organisms which live within have variations in their genetic make up due to random mating. the ones with beneficial genetic variations can express certain traits which give them an upper hand in surviving and reproducing in the said environment compared to ones who may have a more disadvantageous variation in traits. over time, the organisms with an upper hand will survive and reproduce more frequently and pass on their beneficial genes while the others die. the result is evolution, where we observe (usually, but not always) eventually, phenotypic distinct changes.