Over time, sedimentary rock containing phosphorus is gradually uplifted through plate tectonic activity. Follow the phosphorus molecules found in the rock through the whole phosphorus cycle, by numbering
the steps that would follow,
To get you started, Step 1 is "Weathering and erosion of the rock deposits the phosphorus into water."
1. Step 1
Aquatic plants absorb and
assimilate the dissolved phosphorus.
A fish eats aquatic plants.
2. Step 2
3. Step 3
4. Step 4
5. Step 5
Soil washes into a lake, where it
sinks to the bottom to become
sedimentary rock
Decomposition of the dead bear
releases phosphorus into the soil
The bear, after a fruitful life, dies
from old age
Weathering and erosion of the rock
deposits the phosphorus into water.
The fish is caught and eaten by a
bear
6. Step 6
7. Step 7

Now it's your turn to investigate human impact around the world. grab your virtual lab coat and put on your environmental science hat. you will be taking a trip around the globe to explore three locations. at each location, you will investigate the cause and effect relationships of deforestation, desertification, and urbanization. you will also gather evidence of how these factors have impacted the environment over time

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.

Chloroplasts and bacteria are in size. a. similar b. at different ends of the size range c. exactly the same d. none of these