The efficiency of photosynthesis varies with the wavelengths of the light that illuminates the chloroplasts. In an experiment to study the relationship between the incoming light wavelengths and the chemical reactions of photosynthesis using a species of green algae, a researcher labeled the CO2 supply to the algae with 14C, and the H2O with 18O. Which of the following results is expected?

More 14C is found in the algae when it is illuminated by green light than when it is illuminated by violet-blue and red light.
More 18O is found in the algae when it is illuminated by green light than when it is illuminated by violet-blue and red light.
More 14C is found in the algae when it is illuminated by violet-blue and red light than when it is illuminated by green light.
More 18O is found in the algae when it is illuminated by violet-blue and red light than when it is illuminated by green light.

Bisphenol a (often called bpa) is a chemical found in products that people use every day, from water bottles to food containers to children's toys. unfortunately, bpa leaches out of its many products and makes its way into our bodies. what are the health effects of bpa exposure? ongoing research is finding that elevated exposure to bpa can affect a wide variety of developmental and physiological processes, but one of the first studies of bpa's health effects came about because of a simple mistake in the lab. at a laboratory at case western reserve university in 1998, geneticist patricia hunt was making a routine check of her female lab mice. as she extracted and examined developing eggs from the ovaries, she began to wonder what had gone wrong. she noticed that many of the eggs showed problems with their chromosomes, and some had irregular amounts of genetic material, which can lead to miscarriages and birth defects in mammals. she learned that a lab assistant had mistakenly washed the plastic mouse cages and water bottles with a harsh soap, releasing bpa from the plastic. knowing that bpa is an endocrine disruptor, a chemical that can enter organisms and mimic hormones, hunt set out to discover whether it had adversely affected her mice.