Name: ______
Turning pictures into words, and words into pictures….
Everyone has heard the phrase “A picture is worth a thousand words”, but is it possible to create a picture from words? Can we also use a picture to create words? In this activity, we will learn about the biogeochemical cycles and use both pictures and words to create a story about how materials move throughout the environment.
The Water Cycle
The water cycle begins and ends with water vapor. Water vapor is the gas form of water. It is found in the atmosphere. Water vapor makes up about 1% of the air around us. High up in the sky, water condenses around tiny dust particles and forms clouds. As the clouds become saturated, water will fall out of the clouds towards earth. This precipitation comes in many forms but usually is rain or snow. As the rain hits the ground, it can do one of two things; first, it can soak into the ground. This process is called infiltration. Water droplets trickle in between soil particles until the ground is soaked. This water is now called ground water and it will be the source of water for plants. The other thing that water can do when it comes to the earth is flow along the surface of the earth. This doesn’t have to be only in rivers and streams, but runoff can occur on any surface- like down the sides of mountains, across parking lots and into streams and rivers. As we learned from Finding Nemo, all drains lead to the ocean!! This is true for all water!
So how does water make the return trip to the atmosphere? Liquid water and frozen water (ice) can become water vapor by evaporation and transpiration. Evaporation is when liquid water turns into a gas when it warms up. This is caused by the sun warming the surfaces of all the bodies of water on earth- but mainly the ocean because it is the biggest! As water evaporates, it rises and joins other water molecules in the atmosphere. Transpiration is similar but involves plants. Plants absorb water from the ground through their roots. They need this water as one of the ingredients for photosynthesis (the process of making sugar). As water travels up through a plant, some of it escapes through tiny pores (holes) in the bottom sides of the leaves. The sun helps the plant do photosynthesis, but it also warms the water in the leaves and makes it turn into water vapor. It is the exact same process as evaporation but the water is coming out of plants instead of a lake or ocean.
Fill in the following chart as you read the story of the water cycle. This will help you organize your thoughts when it comes time to draw a diagram/picture of the water cycle.
Where it exists
Changing forms
Now define or describe all the words that you wrote in the “Changing Forms” column.
On a separate sheet of paper, draw a diagram of what the water cycle looks like. Use arrows to show how water moves from one form to the next. Label the different types of water (using your list “Where it exists”) and the different forms (from your list “Changing forms”). Use color to make your diagram more professional.
The Carbon Cycle!
The carbon cycle (sometimes called the carbon-oxygen cycle) also begins in the atmosphere. The form of carbon in the atmosphere is carbon dioxide. This form of carbon is called “inorganic” because it is not part of a living organism. Carbon can be turned into an organic form by one very important group of organisms- the autotrophs. Autotrophs are organisms that perform photosynthesis. Photosynthesis is a process that combines water with carbon dioxide to create sugar. This process requires lots of sunlight to power the cell machinery that does this function. So sugar is the main example of organic carbon.
When plants are eaten by animals, this sugar (and therefore carbon) is transferred from the plant to the animal. Animals use this sugar from their food to supply energy to all of the parts and processes in the body that are busy keeping us alive. When we break sugar down during a process of cellular respiration, we release the energy, and also produce water and carbon dioxide! The water is also used in our bodies, but the carbon dioxide is toxic to us and so we get rid of it- by breathing it out. This part of respiration is familiar to us but it is important to understand that there is a lot going on during cellular respiration. Plants actually respire too- they use the sugar they made to provide energy to themselves and produce carbon dioxide. The plants get rid of it when they get rid of water (remember transpiration?). Whether it is a plant or animal, anything that does respiration is returning carbon to the atmosphere.
Sometimes carbon takes a detour before ending back in the atmosphere. Plants and animals also get rid of carbon when they poop or die. Waste products from the body contain carbon and dead animals also contain large amounts of carbon. When poop or dead things get into the soil, bacteria and other decomposers break most of it down and they release the carbon back into the atmosphere in the form of carbon dioxide. Finally, a very small percent of the dead animals a long time ago got locked up in the earth’s crust. Over millions of years, they formed fossil fuels (oil, gas, and coal). When we extract these materials from the earth and burn them, we are releasing the carbon dioxide that was in those dinosaur bodies back into the atmosphere. Humans burn fossil fuels in their homes, in various industries and in their cars.
It is important to note that this whole process is also happening in the ocean but instead of plants, phytoplankton do the photosynthesis and sea creatures like fish do the respiration.
Fill in the following chart as you read the story of the carbon cycle. This will help you organize your thoughts when it comes time to draw a diagram/picture of the carbon cycle.
Where it exists
Changing forms
Now define or describe all the words that you wrote in the “Changing Forms” column.
On a separate sheet of paper, draw a diagram of what the carbon cycle looks like. Use arrows to show how carbon moves from one form to the next. Label the different types of carbon (using your list “Where it exists”) and the different forms (from your list “Changing forms”). Use color to make your diagram more professional.
The Nitrogen Cycle!
One more to go….. This time we are going to create a narrative that will explain how nitrogen flows through the environment. To begin, we need to study the diagram. Fill in the chart below just like we did before. By differentiating between the types of nitrogen and the processes that change nitrogen, we will be able to be clear when we begin to write.
We are going to look at two different diagrams. You may like one better than the other or one may be clearer. They are both explaining the same processes though.
Start be using clues in the diagrams to define the following words.
Detritus
Assimilation
Excretion
Nitrogen-fixation
Denitrification
Now fill out the chart to organize your thoughts.
Where it exists
Changing forms
Finally, write the story of the nitrogen cycle. When you are done, go back and make sure you didn’t leave out any important steps.