1 point 2. In July, a student tested the soil in two plots and calculated the
concentration of nitrogen compounds present in each plot. The student
then planted 20 seedlings in the first plot and allowed them to grow.
Nothing was planted in the second plot. The student tested the soil in both
plots again after one month. The concentration of nitrogen compounds
had decreased in the first plot but had remained the same in the second
plot. Which of the following best explains the decrease in nitrogen
compounds in the first plot? *
A. The nitrogen compounds had broken down into elements.
B. The nitrogen compounds were absorbed by the seedlings for their growth.
C. The nitrogen compounds escaped through air pockets created by the seedlings'
roots.
D. The nitrogen compounds had evaporated because of the warm summer
temperatures.

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.