Mr. Bouyer
Day 1 | Day 2 | Day 3 - 4 | Lab | Vocabulary Test

This Week's

Biogeochemical cycles Water Cycle Evaporation Transpiration	Precipitation Nitrogen Cycle Nitrogen fixation	Ammonification Nitrification Denitrification Carbon-oxygen Cycle

The water cycle: There are about 1.5 billion km3 of water on Earth.   97% of the water on earth is in the oceans. Only 3% of the water on earth is freshwater. About 2.4% of the water on earth is permanently frozen in glaciers and the polar ice caps. About 1/2 of 1 % of the water on earth is groundwater. Only about 1/100 of 1% of the water on earth is in the rivers and lakes.   Most cycling occurs through:   Evaporation Transpiration Precipitation

Test your knowledgeof the water cycle.

Petroleum Engineer

In-class Assignment 271: This assignment must be turned in by the end of class today to receive credit. Scoring criteria How much of Earth's water is found in rivers and lakes? Study this website to answer these questions: Clouds are formed by condensation. What does water condense on to form a cloud? What type of clouds are made of ice crystals? Why does water move horizontally through an aquifer instead of downward? Study this website to answer these questions: During 1995, how many gallons of freshwater were used each day in Texas? What were the top four categories for the use of this freshwater? We all know that the "dust bowl" was caused by the worst drought in Oklahoma's history. Officially, during what years did this drought occur?

Day 2

Your body must have nitrogen to make what compounds?

The nitrogen cycle: converts atmospheric nitrogen, N₂ , into a form plants and animals can use.

Nitrogen makes up about 78% of the atmosphere. However, most living things cannot use atmospheric nitrogen and must rely on nitrates (NO₃^-) and nitrites (NO₂^-) in the soil.

Steps of the nitrogen cycle: Nitrogen fixation - nitrogen-fixing bacteria, primarily living on the roots of legumes, convert nitrogen gas into NH4OH. Ammonification - bacteria decomposers break down amino acids from dead animals and animal wastes into NH4OH. Nitrification - chemosynthetic bacteria oxidize NH4OH to produce nitrates and nitrites. The energy of lightning also causes atmospheric oxygen and nitrogen to combine to form nitrate ions. Denitrification - anaerobic bacteria break down nitrates, releasing N2 back into the atmosphere.

This is a slow process requiring a lot of energy. Because of this, lack of nitrogen in the soil often limits the productivity of an ecosystem.

End Of Instruction practice test question #31

Concept Understanding: Study this website to answer this question: What four activities of humans have severely altered the nitrogen cycle?

Day 3 - 4

What is the cause of the increase in the amount of CO2 in the Earth's atmosphere?

Carbon-oxygen cycle: Photosynthesis removes CO2 from the air and adds O2. Cellular respiration removes O2 from the air and adds CO2. Photosynthesis and respiration usually balance out. Decomposers break down organic material releasing CO2. Increased levels of CO2 in the atmosphere trap more heat and increase the possibility of global warming.

In-class Assignment 274:
This assignment must be turned in by the end of class tomorrow to receive credit.

1. Coal, oil, and natural gas are fossil fuels. Use this essay planning guide to write an essay about how one of the fossil fuels is formed.

Biology Class

Ocean water is "salty" because of its dissolved minerals.
River waters carry dissolved minerals to the ocean. When water evaporates from the ocean, the minerals are left behind. This leads to a continual increase in the concentration of minerals in ocean water.

Your body must have nitrogen to make amino acids.
Amino acids are the building blocks of proteins.

Increasing human population is the reason CO₂ levels are increasing in the Earth's atmosphere.
Carbon dioxide is a waste product given off during respiration and the burning of hydrocarbons.