Grade 5 RCA - Wappingers Central School District · foot race? A good scientist ... When you drop...

Grade Five

In the Reading in the Content Area section, you will find several readings that may be used for Unit 1. They can serve as an English Language Arts connection to this unit. These readings also provide important background information for the students. The readings for this unit provide support for the lessons. Teachers should look ahead at the selections and duplicate those readings that are appropriate prior to or during the various activities that the readings are intended to support.

List of Readings

Reading In The

Content Area

87

SCIENCE 21: Science For The 21st Century Interactions of Chemical Matter

GRADE 5 • UNIT 1 • READING IN THE CONTENT AREA

Think Like A Scientist………………………… pg. 89 Daniel Gabriel Fahrenheit……………………….. pg. 93 The History of the Baby Diaper…………………. pg. 97 ’Speedy’ Alka Seltzer…………………………… pg. 101 Atoms and Molecules…………………………… pg. 105

©2004, Putnam/Northern Westchester BOCES • SCIENCE 21 • Grade 5 • Unit 1

Grade 5, Unit 1, Reading in the Content Area

Think Like a Scientist Do you think like a scientist? If you needed to find out information on a particular subject, where would you look? Good places to start are encyclopedias, nature magazines, other magazines, and the Internet. You must be careful using information that you find in these sources. A good scientist never believes what he or she reads without carefully questioning the information and how it was obtained. Suppose you are researching information about how fast animals can run and you locate the following information in one of your sources: Using the information from this chart, do you think a person could ever outrun a cheetah in a foot race? A good scientist would question this chart before answering the question. Does the information on animal speeds appear logical? What do miles per hour mean? Does it mean that if an animal runs at its fastest speed for one hour it will travel the number of miles stated? For example, if an elephant runs at its top speed for one hour, it will travel 25 miles. Thinking like a scientist, do you believe that an elephant can run for one hour without stopping? Have you ever seen a cat run for a mile without stopping to rest? Most animals can run at high speeds for only a short period of time. They tire and need to stop to rest. An elephant is speedy, but only for a short distance. Other animals can keep up fast speeds for longer distances, but not for one hour. If most animals are unable to maintain top speed while running a mile, where do the speeds on the chart come from? These speeds were based on the recorded speeds of animals over short distances. These speeds are then converted into the number of miles these animals could travel in one hour, if they were able to maintain their top speeds all the time. This information could therefore be misleading if you didn’t investigate and carefully think about it.

Animal Speed (miles per hour)

Cheetah 70 Horse 48 Ostrich 45 Rabbit 35 Bear 32 Cat 30 Rhinoceros 28 Elephant 25 Fastest Human 22 Squirrel 12

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Name _________________________________ Date ___________________ Answer the following questions: 1. According to the chart in the article, how fast can the fastest human travel? ____________________________________________________________________ 2. In a marathon (about 26 miles) the fastest time ever recorded was a few minutes more than two hours. According to the chart, a human should be able to run much faster. Ex plain why the chart is misleading. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 3. If the animals listed in the chart had a race, do you believe they would always finish in the order in which they are listed in the chart? Explain your answer. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 4. Could a person ever win a foot race with a foot race with a cheetah? Explain your answer. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________

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Daniel Gabriel Fahrenheit

Since early times people have known that many substances expand when they are heated and contract when they are cooled. In the 1500's, scientists used this knowledge to build instruments for measuring temperature. The liquid in the narrow tube would expand as it was heated. (This is principle used in our present-day thermometers.) These instruments were of limited use in studying the weather since they were filled with water which would freeze when the weather was cold. The first thermometers were constructed around 1600 by Galileo. These were gas thermometers, in which the expansion or contraction of air raised or lowered a column of water, but fluctuations in air pressure caused inaccuracies.

In 1709, Daniel Gabriel Fahrenheit, a German physicist, developed an alcohol-filled thermometer that could be used to measure temperatures below the freezing point of water. In 1712, Fahrenheit improved his thermometer by using mercury. This allowed people to measure temperatures even farther below the freezing point of water and above water’s boiling point. The mercury thermometer was also more accurate since mercury expands and contracts at a more constant rate than alcohol and water.

Fahrenheit arbitrarily decided that the freezing and boiling points of water would be separated by 180 degrees, and he pegged freezing water at 32 degrees. So, he made a thermometer, stuck it in freezing water and marked level of the mercury on the glass as 32 degrees. Then he stuck the same thermometer in boiling water and marked the level of the mercury as 212 degrees. He then put 180 evenly spaced marks between those two points thus creating the Fahrenheit scale.

In creating the Celsius scale, Andres Celsius arbitrarily decided that the freezing and boiling points of water would be separated by 100 degrees, and he pegged the freezing point at 100 degrees. His scale was later inverted, so the boiling point of water became 100 degrees and the freezing point became 0 degrees.

As you can see, the temperature scales we commonly use are completely arbitrary! You could come up with your own scale if you wanted to. The freezing and boiling points of water are nice because they are easily reproduced, but there is nothing to say you couldn’t use another scale.

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Name _________________________________ Date ___________________ Answer the following questions: 1. What is the word used in the article that means to get smaller? ____________________________________________________________________ 2. What was the problem with the early thermometers? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 3. What was the advantage of using alcohol in a thermometer? ____________________________________________________________________ ____________________________________________________________________ 4. What did Fahrenheit decide the freezing and boiling points of water should be? Why? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 5. If you were to create a temperature scale, what would you call it and what would you peg as the freezing and boiling points? ____________________________________________________________________ ____________________________________________________________________ __________________________________________________________________________________

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The History of the Baby Diaper

The need for a diaper for a baby dates as far back as the history of mankind. No matter how beautiful the Garden of Eden was, Adam & Eve had a need for the baby diaper. Many ancient documents refer to special clothing used for babies in early times. Milkweed wraps, animal skins, and other creative natural resources were used as a diaper. The Egyptians, the Aztecs, and the Romans, all left documentation of the use of special clothing for wrapping babies.

Infants have been wrapped in swaddling bands in many European societies since antiquity. Swaddling bands were strips of linen or wool that were wrapped tightly around each limb and then crosswise around the body (like many yoga advocates still do in India.) In Elizabethan times, babies were treated to a fresh diaper only every few days. In some Native American tribes, mothers packed grass under a diaper cover made of rabbit skin, and this same method was also used by the Incas in South America.

In warmer tropical climates, babies were mostly naked and mothers tried to anticipate a baby’s bowel movement to avoid any mess near the house. In the American West, during pioneer times, wet diapers were seldom washed. Most times, these diapers were just hung by the fireplace to dry and then used again. In Europe, it wasn’t until the Industrial Revolution in the 1820's, that workers started making an effort to carefully contain their babies waste, since acquiring sufficient wealth they now needed to protect the new furnishings they could now buy for their homes.

By the late 1800's, infants in Europe and North America were wearing what is considered the beginning of the modern diaper. A square or rectangle of linen, cotton flannel, or stocking net, was folded into a rectangular shape and held in place with safety pins. At the beginning of the twentieth century, with a better understanding of bacteria, viruses, fungi and

how to control and eliminate them, many mothers started to use boiling water to wash diapers, in order to reduce the common diaper rash problem. A big steel pot was used to boil water for the used diapers to be washed, and then the wet diapers were hung to dry in the sun.

During the World War II years (1939 - 1945,) the increase in working mothers created the need for “diaper service.” Fresh cotton diapers would be delivered to the home on an as needed basis and soiled diapers would be picked up. As with many of the greatest inventions, it is not clear who can be credited as the “single” inventor of the disposable diaper, since it came about by the addition of many gradual steps. In the late 1950's, Vic Mills, a scientist for the Proctor and Gamble company, invented “Pampers” as he was searching for better products to use for a baby grandson. The 1960's and 1970's, saw minor improvements in the disposable diaper. In 1984, with the introduction of the super-absorbent diaper (sodium polyacrylate) a new generation of diapers was created. Diapers were now thinner, had improved retention, which helped reduce leakage and prevent diaper rash.

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Name _________________________________ Date ___________________ Answer the following questions: 1. What were some of the early materials that were used for diapers? ____________________________________________________________________ ____________________________________________________________________ 2. What problems can arise if diapers are not washed? ____________________________________________________________________ ____________________________________________________________________ 3. How did the Industrial Revolution create a need to be more careful in containing a baby’s waste? ____________________________________________________________________ ____________________________________________________________________ 4. What caused diaper rash? How was it controlled? ____________________________________________________________________ ____________________________________________________________________ 5. What brought on the need for diaper service? ____________________________________________________________________ ____________________________________________________________________ 6. What was the major breakthrough in the development of disposable diapers? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________

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“Speedy” Alka Seltzer

Why does Alka Seltzer fizz? The fizzing you observe when you drop an Alka Seltzer tablet into water is the same type of fizzing that you also see from baking soda. This reaction is caused by the meeting of an acid (citric acid), with the baking soda (sodium bicarbonate.) If you look at the ingredients contained in Alka Seltzer, you will discover that it contains citric acid and sodium

bicarbonate. When you drop the tablet in water, the acid and baking soda react producing the fizz. Alka Seltzer was first introduced in 1929 as an antacid (an alkaline remedy for stomach acidity.) After World War II, the Miles Pharmaceutical Company was looking for a spokesperson to represent their product “Alka Seltzer” and help sell this bicarbonate product.

Bob Watkins, submitted several sketches of a character he originally called “Sparky” to the pharmaceutical company. His Alka Seltzer tablet body with hat and “effervescent” wand first appeared in a woman’s magazine in the spring of 1952, under the name “Speedy.” However, it wasn’t until his appearance on television, that Speedy really came to life.

From 1953 - 1964, Speedy appeared in 212 commercials. Speedy was shelved in the late 1960's, but returned for America’s Bicentennial in 1976 and the 1980 Winter Olympics. He now periodically appears sporting glasses and a Hawaiian shirt. This is not bad for a little guy that took only three hours to be developed as a character.

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Name _________________________________ Date ___________________ Answer the following questions:

1. Why does Alka Seltzer fizz? _______________________________________________ ____________________________________________________________________ ____________________________________________________________________ 2. What is an antacid? ______________________________________________________ ____________________________________________________________________ 3. Why do you think they chose to call the spokesperson Speedy? ____________________________________________________________________ ____________________________________________________________________ 4. Why do you think Speedy was displayed at the Bicentennial celebration in 1976? ____________________________________________________________________ ____________________________________________________________________ 5. Why is it important to come up with a “catchy” name when trying to sell a product? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________

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Atoms and Molecules Matter is anything that has mass and takes up space. Everything you can touch is made of matter. All matter is made up of atoms and molecules. Atoms are the smallest particles of an element. Elements are made up of only one kind of atom. For example, hydrogen, oxygen, iron, gold, calcium, etc. are all elements. All atoms of each element are exactly the same and different from the atoms of any other element. Elements cannot be separated into simpler substances. When two or more atoms combine, the result is a molecule. Molecules are the smallest particles of a compound. For example, water is a compound and each water molecule is made up of two atoms of hydrogen and one atom of oxygen, hence the formula H2O. (The small two [2] that is lower than the “H” and the “O” is called a subscript and it means that two atoms of hydrogen and one atom of oxygen are combined together.) Molecules can be very, very large as many combinations of atoms join together, but they are still too small to see, even with a very good microscope. Let’s say that you keep tearing a piece of paper into smaller and smaller pieces. Eventually (using tools that we do not have in our schools) you would reach a point where you could not cut the paper anymore and still have paper. You would then have molecules of paper. Eventually, if you could break the molecules apart (and this is not as easy as it might seem) you would be left with the individual atoms that made up the paper molecule. If you continually cut up a piece of aluminum, you would reach a point where you could no longer divide it and still have aluminum. Then, you would be left with an aluminum atom. So, an atom is thus the smallest particle of an element that is still the element. Each element and each compound has its own, unique, physical properties. Some of the properties of the element aluminum are: shiny, silver colored, ductile (can be shaped into thin sheets). Some of the properties of the compound water are: liquid at room temperature, colorless, odorless. Elements and compounds are called pure substances because they are made of only one kind of simple particle. Salt water, on the other hand, is not a pure substance. It is a mixture of two compounds, salt and water, and it can be separated into the salt and water by evaporating all the water. Chemists use symbols to represent each element. A symbol is a letter or a picture that represents something. Chemists use one or two letters to represent elements. Some of the ones that you might be familiar with are “Al” for Aluminum; “O” for Oxygen; “He” for Helium; “Fe” for Iron; “C” for Carbon; “Kr” for Krypton. Even though the atom is the smallest unit of an element, each atom is made of smaller particles. The three main particles in an atom are protons, neutrons, and electrons. The protons and neutrons are located in a tiny center of the atom, called the nucleus. Protons carry a positive (+) electrical charge. Neutrons do not have an electrical charge and they are considered neutral. Electrons carry a negative (-) charge.

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Grade 5, Unit 1, Reading in the Content Area You may remember this from your study of electricity. The nucleus is surrounded by the negatively charged electrons. Electrons can be anywhere in a cloudlike region around the nucleus. Once you understand about the smallest parts of matter, you can begin to see how these various pieces join together to form more and more complex pieces of matter. This is the basic structure of all the things that we are familiar with on Earth! Answer the questions on the following page.

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Name _________________________________ Date ___________________ Answer the following questions:

1. How would you define matter? _____________________________________________ ____________________________________________________________________ ____________________________________________________________________ 2. A substance that is made up of only one kind of atom is called: ____________________ 3. What are the three main parts of an atom: ________________________________ ____________________________ and ________________________________ 4. When two of more atoms combine, the result is a _______________________________ 5. The symbol for the molecule Carbon Dioxide is CO2. What are the names of the atoms that comprise Carbon Dioxide? ____________________________________________________________________ 6. In the Carbon Dioxide molecule, how many of each type of atom need to combine to form the molecule? ____________________________________________________________________ BONUS! 7. What do you call a molecule that is made up only of the same kind of atoms? ____________________________________________________________________

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List of Readings

Reading In The

Content Area

197

SCIENCE 21: Science For The 21st Century Interactions in the Microworld


Microscopes for the Microworld……………………. pg. 199 The Cell Theory…………………………………… pg. 203 Cells: From One to Many………………………… pg. 207 Characteristics of Living Things……………………. pg. 211 Our Battling Blood Cells……………………………. pg. 215


Parallel light rays

Convex Lens

Gathers light to focal point, then spreads the light to make the image larger. Focal

point

Microscopes for the Microworld

Because our senses can sometimes mislead us or not provide enough information, we need to utilize tools of magnification. These tools, the hand lens and microscope, help us to better explore our world and therefore make more accurate observations and measurements. Regular window glass is flat on both sides allowing light to travel straight through. Hand lenses and microscopes use a glass lens that is curved on both sides. As light passes through this lens, it is bent, which makes the image appear larger than it actually is. The result is magnification.


A hand lens uses one curved lens, and a microscope uses a series of curved lenses to enlarge objects. Micro means small and scope means to look at, so a microscope is a tool that is constructed to look at very small things. A simple lens microscope only uses one lens, whereas a compound microscope uses two or more lenses. The first compound microscope using two lenses was created by father and son team of lens grinders, Hans and Zacharias Janssen. In 1665, Robert Hooke, an English scientist, looked at a thin slice of cork (oak cork) through a compound microscope and observed tiny, hollow, room-like structures. Because these structures reminded him of the rooms where monks lived, he called them “cells.” Robert Hooke only saw the outer walls (cell walls) because cork cells are not alive. The world’s first high powered microscope was constructed by a Dutchman, Anton van Leeuwenhoek. It magnified images of objects nearly three hundred times their normal size. Using his microscope, Leeuwenhoek was able to make some astounding discoveries. Under his microscope, he was able to observe tiny swimming creatures in a drop of water. When observing a drop of blood, he saw saucer-shaped blobs, and skin resembled the bricks of a wall. Leeuwenhoek was the first person to observe cells. Today, Electron Microscopes, function the same way that optical microscopes do, except that they use a focused beam of electrons instead of light to view the specimen. Electron microscopes can magnify images more than 200,000 times the actual size. Scientists have actually seen the structure of atoms in large molecules using electron microscopes.

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Name _____________________________ Date ______________________ Answer the following questions: 1. How does a lens magnify objects? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 2. Why did Robert Hooke name the structures he observed under his microscope “Cells”? ____________________________________________________________________ ____________________________________________________________________ 3. What was significant about Anton van Leeuwenhoek’s microscope? ____________________________________________________________________ ____________________________________________________________________ 4. What were van Leeuwenhoek’s astounding discoveries? ____________________________________________________________________ ____________________________________________________________________ 5. Why was Leeuwenhoek and not Robert Hooke credited with being the first person to see living cell? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________

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Cell Theory Historical Timeline

The Cell Theory

Improvements in the microscope and microscopic technique over the last three centuries, have allowed scientists to study cells more carefully and develop a theory to explain the nature of cells. There have been various contributions which led to the development and acceptable of the cell theory of life. In 1590, the first compound microscope was produced by Hans and Zacharias Janssen. In 1665, Robert Hooke first identified spaces in cork and labeled them “cells,” and in the 1680’s, Anton van Leeuwenhoek observed living cells through a simple microscope. Matthias Schleiden, in 1838, discovered that animals are made of cells. The discovery by Rudolph Virchow, in 1855, stated that living cells come from other living cells. The cell theory eventually came to be stated in three parts as additional data provided evi-dence that:

• All living things are made of cells • Cells are the basic unit of structure for all living things, and • Cells come from other living cells.

The final statement is evidenced by cell reproduction. This process is called mitosis or cell division. Mitosis is cell division that takes place in the cell nucleus. Chromosomes, the genetic material in the cell nucleus, duplicates itself and then separate into two new cells that are exactly alike. This process is controlled by the nucleus through a series of complex steps. In the process, the new daughter cells are created that are exact duplicates of the original cell.

Grade 5, Unit 2, Readings in the Content Area Plant cells also reproduce by cell division. Like animal cells, plant cells make copies of themselves and carry out mitosis. The only difference is that in plant cells, a new cell wall and a new cell membrane form down the middle of the cell. The debate over whether living things could come from non-living matter raged for years until the cell theory and the work of Louis Pasteur provided evidence that cells only come from other cells. Even today, as scientists push the frontier of research trying to determine how life first started on Earth, all agree that once a living organism was first formed, only life could beget new life.

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Grade 5, Unit 2, Reading in the Content Area Name _____________________________ Date ______________________ Answer the following questions: 1. What theory did the scientists in the previous article provide evidence for? ____________________________________________________________________ 2. What instrument was necessary before the cell theory could be developed? ____________________________________________________________________ 3. Which three scientists directly contributed evidence for the cell theory? _____________________________________________ _____________________________________________ _____________________________________________ 4. How did the earlier scientists and their contributions directly affect the discoveries of later scientists? What had to come first? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 5. List the three parts of a cell theory? ______________________________________________ ______________________________________________ ______________________________________________

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Cells: From One to Many

All living things are made up of one or more cells. Many cells have specialized functions or work to do. An example of a cell with a specialized function would be human red blood cells, which are specialized to carry oxygen. Other specialized human cells include epithelial, muscle, nerve and bone cells. A group of the same kind of cells that carry on the same function or work is collectively referred to as a tissue. A group of different tissues all working together to perform a specific function is called an organ. A group of organs all working together to perform a specific function is called a system. Thus, the organs of stomach, pancreas and intestine, among others, are all made up of different tissues, but they work together as the system that is responsible for digestion. All the systems working together, make up an organism. The human body is made up of trillions of cells classified as animal cells. They are very specialized in size, shape, function and make-up. There are five main kinds of tissue in the human body. Muscle tissue is found in all the parts that enable us to move. Nerve tissues enable us to interact with our environment. Epithelial tissue lines our insides and outside (skin, mouth and nose linings, heart, stomach and liver linings). Connective tissue holds everything inside together (ligaments, tendons, cartilage and bone are examples). Blood, although a liquid, is also a tissue and it is responsible for the distribution of materials throughout our bodies. Blood carries the materials that we need to survive.

All these tissues compose our organs, each of which has a specific function. So our stomach may have a number of tissues that make it up, but it has a purpose, that being to contain acid that breaks down certain food items we eat. The human body is made up of ten large systems or groups of organs. They are: skin, skeletal, muscular, digestive, circulatory, respiratory, excretory, nervous, reproductive and endocrine (which is the gland system that gives off many chemicals to regulate the action of the rest of the body). It is amazing that all of these various parts work together to keep our bodies going!

Muscle Tissue

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Name _____________________________ Date ______________________ Answer the following questions: 1. What do we call a group of the same kind of cells that out the same function? _______________________________________________________ 2. What do we call a group of organs that work together to perform a specific function? _______________________________________________________ 3. What do we call a group of different tissues that work together to perform a specific function? _______________________________________________________ 4. Pick one of the human body’s systems and list as many organs that are a part of that system as you can. ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 5. Look at the chart below and fill in the blank space. Explain your reason for your choice.

Student = Cell

Class = Tissue

Grade = Organ

_____ = System

District = Organism

___________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________

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Characteristics of Living Things

It is not always easy to tell the difference between living, dead, and nonliving things. Prior to the 1600's many people believed that nonliving things could spontaneously turn into living things. For example, it is believed that piles of straw could turn into mice. This is obviously not the case. There are some very general rules to follow when trying to decide if something is living, dead, or nonliving.

Here are the six rules used by scientists to make their decision:

• Living things are made of cells. • Living things obtain and use energy. • Living things grow and develop. • Living things reproduce. • Living things respond to their environment. • Living things adapt to their environment.

If something follows one or just a few of the rules listed above, it does not necessarily mean that it is living. To be considered alive, an object must exhibit all of the characteristics of living things. Sugar crystals growing on the bottom of a syrup container is a good example of a nonliving object that displays at least one criteria for living organisms. A candle can also exhibit one or more of these characteristics.

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Grade 5, Unit 2, Reading in the Content Area Name _____________________________ Date ______________________ Answer the following questions: 1. Why would people in the 1600's believe that piles of straw could turn into mice? ____________________________________________________________________ ____________________________________________________________________

2. List the 6 rules used by scientist to determine if something is living, dead or nonliving? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________

3. Why might sugar crystals be mistaken for a living object? ____________________________________________________________________ ____________________________________________________________________ 4. Viruses are not considered living. Why? ____________________________________________________________________ ____________________________________________________________________

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Our Battling Blood Cells

All living things are made of cells. A cell is a tiny unit of living material that is the basic building block of life. Certain cells can cause a great deal of trouble in the human body, while other cells have the job of defending and protecting the body. Whether you’re healthy or ill, depends on which cells, the helpful or harmful, are in control.

Whenever a germ or infection enters the body, the white blood cells snap to attention to protect you. When germs appear, the white blood cells have a variety of ways by which they can attack them and protect you. They defend us against germs that make us sick, and this defense is our immune system.

The immune system decides what belongs in our body and what does not. If we get a splinter, cut or scrape under our skin, that brings bacteria with it, our immune system goes to work. Large white blood cells called phagocytes (phag-o-cytes), have the job of attacking and eating any dangerous organism that doesn’t belong there. The redness and soreness that appear around a cut on the skin, or the pus that often gathers there, are indicators that the phagocytes are at work.

If the germs get past our body’s skin cells, another type of white blood cell appears on the scene. These cells, called lymphocytes (lym-pho-cytes), destroy the invader by punching holes in their cell walls. They help create antibodies that attach to the harmful organism and hold them until other white cells can destroy them.

The white blood cells have a rather short life cycle. They can survive a few days or a few weeks. A drop of blood may contain anywhere from 7,000 to 25,000 thousand white blood cells at a time. If an invading infection fights back and persists, that number will increase significantly. A consistently high number of white blood cells are symptoms of Leukemia. A leukemia patient may have as many as 50,000 thousand white blood cells in a single drop of blood.. The uncontrolled growth of these blood cells begin to fill the marrow crowding out other cells that are important for our health and well-being.

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Grade 5, Unit 2, Reading in the Content Area Name _____________________________ Date ______________________ Answer the following questions:

1. What determines whether you are healthy or ill? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________

2. Why are white blood cells called “defenders of the body?” ____________________________________________________________________ ____________________________________________________________________ 3. What is the function of antibodies? ____________________________________________________________________ ____________________________________________________________________

4. What is Leukemia and why is it a dangerous disease? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________

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List of Readings

Reading In The

Content Area

203

SCIENCE 21: Science For The 21st Century Interactions in the Human Body


Strange Breathing Occurrences……………… pg. 205 The Heart in History………………………… pg. 209 Broken Bones, Healing Bones………………… pg. 213 Muscles on the Move………………………….. pg. 217 DNA and Solving Crimes!…………………….. pg. 211



Strange Breathing Occurrences

Every time we breathe in and out, our lungs are hard at work. When we breathe in air, it enters through our nose or mouth, it passes our larynx (voice box) and then enters a large pipe called the trachea (windpipe). It then travels down our chest and the windpipe branches off into two smaller tubes (the bronchi). Each of the bronchi tubes bring air to your lungs. When you breathe out, the air travels out using the same route. The main purpose of breathing is to get oxygen from the air. Oxygen is necessary for energy and the life of the cells in our body. We breathe out to get rid of waste gas called carbon dioxide. If you exhale through your mouth onto the palm of your hand, you will notice that the air feels warm. If you do the same against a mirror, the surface of the glass will mist up, which shows that the air you exhaled has moisture (water vapor) in it.

Sometimes, strange things can occur when we are breathing. These odd occurrences help to keep us healthy. No one is exactly sure why we hiccup. Our body has a muscle below our lungs called a diaphragm. Sometimes the diaphragm squeezes together harder than usual, and you hiccup. As you breathe in, the space between your vocal cords snaps shut which then makes that strange hiccup sound. Have you ever noticed that babies hiccup a lot?

When we yawn, we give our body a big dose of oxygen. When you’re tired or just sitting still for a long time, your breathing slows down and when this occurs, you take in less oxygen. If your body needs more oxygen, you may yawn. Yawning pulls more oxygen into your lungs which gives you more energy and helps you stay awake.

Coughing is your body’s way of pushing out unwanted substances. Your throat and windpipe are coated with a slimy substance called mucus. Mucus helps to trap tiny bits of dust and other unwanted things that enter our body. When too many bits get into the mucus in your throat, you cough. Coughing stops these bits from reaching your lungs.

When you go swimming, you cannot breathe underwater. This is because our lungs need a gas not a liquid to breathe. Only a gas like oxygen and carbon dioxide can move through your lungs. A liquid such as water, cannot move through your lungs fast enough for you to breathe. You cannot survive if you are unable to breathe. That is why when swimming underwater, we need to hold our breath.

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Name _____________________________ Date ______________________ Answer the following questions: 1. Why do we breathe? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 2. Explain why we yawn. ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 3. Why is coughing helpful? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 4. Why can’t we breathe underwater? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________

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The heart is a muscular organ about the size of an adult fist. It controls the circulation of blood. It is made up of four chambers and is divided down the middle by a thick wall of muscle, the septum. The right side of the heart pumps blood into the lungs, the left side which is more muscular, pumps blood throughout the body.

While ancient people knew the heart was important, they didn’t know why. Ancient Egyptians believed that the heart was the center of emotion and intellect and that blood vessels started in the heart and linked it to the rest of the body. But they also believed that these vessels also carried other fluids like tears and urine along with blood. In the Fifth Century BC, Hippocrates, the father of medicine, described the heart as having valves, atria and ventricles that contract at different times, and great blood vessels extending from it. Unfortunately, he didn’t understand the difference between arteries and veins.

In the Second Century, Galen, a Greek physician discovered that blood circulates through the heart and lungs, but his drawings depicted the esophagus leading directly to the heart and not the stomach. His drawings were used for the next fourteen hundred years. A Flemish physician named Andreas Vesalius published an anatomy text in the 16th century based on the human body. He was the first to use humans, not animals, in his drawings. But he too confused the arteries with the veins. Amid all these misunderstandings, a Chinese medical book from approximately 3,000 years ago, correctly reported that the heart regulates all the blood in the body and that blood flows continually in a circle. Western civilizations didn’t reach this same conclusion until the 17th century. The human body is a complex machine with many parts that sometimes break down. For many years Cardiologists (doctors who specialize in the heart) thought the heart was too complicated and delicate to fix. The first successful heart surgery was performed in 1893, by Dr. Daniel Hale Williams, an African-American doctor in Chicago. When the heart cannot be repaired, it must be replaced. A new heart can now be transplanted from a person who just died. Today, doctors are able to transplant a healthy heart to patients whose hearts could not be repaired. The first human heart transplant was performed by Dr. Christian Barnard of South Africa in 1967. Research studies are being conducted on the development of an artificial heart that can be permanently implanted within a person’s chest wall.


The Heart in History


Name _____________________________ Date ______________________ Answer the following questions: 1. Doctors who specialize in the heart are called? ______________________________________________________________________ 2. What did the Egyptians believe about the heart? _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ 3. Which group first concluded that the heart regulated all the blood in the body and that blood flowed in a circle? _______________________________________________________________________ 4. Why was Andreas Vesalius’ work important? _______________________________________________________________________ 5. What do you think will be the next major development in heart research? _______________________________________________________________________ _______________________________________________________________________ 5. What are some of the ways we can keep our heart healthy? _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________

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Broken Bones, Healing Bones There are many bones inside our body that make up our skeleton. The biggest bones are located in our thighs and the smallest in our ears. Your bones are the framework for your body, just like the framework on a building. If you didn’t have bones, you would not be able to stand, walk or run.

Bones are made of minerals and collagen. These minerals, particularly calcium and phosphorus, make bones hard. Collagen, a strong flexible fiber, makes bones slightly elastic so they don’t snap. The outer layer of the bones is dense and tough and is called hard bone. The inner part of the bone is lighter and looks like a sponge. It is called the spongy bone. In the hollow middle center is a jelly like substance— bone marrow. This important substance makes most of the blood cells that flow through the body. Although bones are quite strong, they can break when put under a lot of pressure. A break in a bone is called a fracture. Bones can break in many different places. A simple or closed fracture is a snapped or cracked bone that doesn’t break through the skin. When the broken parts of the bone break through the skin, you then have a compound or open fracture. Doctors usually can tell the exact nature of a fracture by taking an X-Ray of the bone.

All broken bones rapidly mend themselves in some way. First a blood clot forms to close up the space between the broken ends, and then bone cells begin to grow on each side of the break. These cells gradually close the gap with new bone tissue. Any bone that is fractured must be realigned and immobilized by a splint or cast. This is called setting. Healing depends upon a person’s age. The younger the person, the shorter the healing time. Bones are vital living parts of our body. We need to continually work at keeping them healthy. Bones need calcium, and when they are deprived of or lose calcium, Osteoporosis can occur. This disease makes bones brittle and more likely to break. Exercise, dietary Vitamin D and calcium are helpful in alleviating this disease as people age. To keep bones healthy, we should make sure that we get sufficient amounts of dairy products such as milk, cheese, and yogurt.

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Name _____________________________ Date ______________________ Answer the following questions: 1. What are bones made of? ______________________________________________________________________ 2. Explain the difference between a simple fracture and a compound fracture. ______________________________________________________________________ ______________________________________________________________________ 3. What is Opsteoporosis? ______________________________________________________________________ ______________________________________________________________________ 4. What can you do to keep your bones healthy? ______________________________________________________________________ ______________________________________________________________________ 5. Name some animals that do not have bones. ______________________________________________________________________ ______________________________________________________________________ 5. What do you think the human figure would be like without bones? ______________________________________________________________________ ______________________________________________________________________

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Muscles on the Move We have muscles all over our bodies. They are the engines that make our body go. They turn energy into a force that produces movement. Muscles enable us to run, jump, laugh, dance, breathe and smile. There are more than 650 muscles in our body. The largest muscles are in your buttocks, and the smallest are in your ear. A muscle is made up of muscle fibers which are bundles of long thin cells. Each fiber is made up of even tinier threads called myofibrils. And every myofilbril contains thousands of even thinner myofilaments. There are three main types of muscle in your body: skeletal, smooth, and cardiac. Skeletal or voluntary muscle, are the types of muscle (like those in our arms and legs) we can move whenever we want. Although many skeletal muscles pull on bones, they are not attached directly to them. Muscles are connected to bones by tough, and cord-like tissue called tendons. The muscle pulls on the tendon and the tendon in turn pulls on the bone. Some muscles have names which show their actions. A flexor muscle (biceps) bends (flexes) a limb at a joint. A corresponding muscle the extensor muscle (triceps) extends or straightens the limb at a joint. The sphincter muscle is a ring-shaped muscle whose contractions narrow the opening of the ring. This muscle is found in our lips, at the ends of our stomach, and the opening of the anus. Often skeletal muscles only move parts of the body like when you wink your eye, or kick your leg, or when you chests’ rises and falls when you’re breathing. Smooth or involuntary muscles are not under our control. They perform automatic actions that are vital for the proper functioning of our body. They play an important part in digestion, circulation and respiration. The most important muscle in our body is the cardiac muscle. The word cardiac comes from a word meaning heart. This muscle makes up the walls of the heart. The heart which is constructed of a special striated muscle called myocardium or cardiac muscle is an involuntary muscle. During a heartbeat, the muscles contract, shortening and hardening the muscles in the heart chambers and these contractions pump the blood from one chamber to another throughout the body. It is very important to keep muscles healthy. A healthy diet and physical exercise are important for keeping muscles fit. Muscles that are not used become weak. Slouching on a couch is not good for muscles. Swimming is an excellent exercise because it uses many muscles. We strain muscles when we pick up heavy items incorrectly. A strain is muscle fiber that is stretched too far or tears. Take care of your muscles and keep smiling. Smiling uses about 20 muscles.

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Name _____________________________ Date ______________________ Answer the following questions: 1. Why do we need muscles? ______________________________________________________________________ ______________________________________________________________________ 2. What are the three types of muscles in our body? ______________________________________________________________________ 3. How are muscles attached to bones? ______________________________________________________________________ ______________________________________________________________________ 4. What is the most important muscle in our body? ______________________________________________________________________ 5. What do you think is the purpose of the sphincter muscles that are located at the two ends of the stomach? ______________________________________________________________________ ______________________________________________________________________ 6. How can we keep our muscles healthy? ______________________________________________________________________ ______________________________________________________________________

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DNA and Solving Crimes!

Each of us started life as a single cell. By the time we are born, we are made up of about one hundred million cells. These cells are microscopic in size. What is truly amazing, is that almost every cell in our body has the same DNA that was in our first cell. DNA stands for deoxyribose nucleic acid. (Don’t worry, you won’t need to know that for a quiz on Friday!) DNA is a very complicated molecule that contains all the genetic information to build a living thing. Genetics is the study of how living things pass on their characteristics from one generation to the next. You inherit your DNA from both your parents, and you will pass some of it on to your children. All the cells in our body contain the same genes which give instructions for building all the parts of the body. Each of these genes contains several thousand code words which define who we are. Because every person is different, every person has different DNA. But the DNA in every different cell in every part of your body is exactly the same. Forensic science is a term used to group together all different sciences in order to solve a crime. The word Forensic comes from the ancient Greek word “forum,” meaning courts of law. Forensic scientists use scientific processes to work with law enforcement personnel to find and collect evidence to solve crimes. Clues that are gathered to help solve a crime are called evidence. Whenever you go anywhere, you leave behind evidence that you were there. It could be a fingerprint, footprint, or a strand of hair. The science of fingerprinting is called dactylography. In the late 1800's, an Englishman, Sir Edward Henry, discovered and identified the four different types of fingerprints. Although there are four fingerprint patterns (arch, loop, whorl, composite), each person in the world has his or her own unique set of prints. There are no two identical sets of prints.

Whenever you walk on soft ground, you leave a footprint. The angle of the footprints and the distance between them gives forensic scientists information about your height and how fast you were going. All hair strands are made up of a protein called keratin. When scientists look at a hair under a microscope, they can analyze the hair and find out information about the person to whom it belonged. Today, DNA profiling is the most important breakthrough in forensic science since the discovery of fingerprinting.

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Name _____________________________ Date ______________________ Answer the following questions: 1. Why is DNA important? ______________________________________________________________________ ______________________________________________________________________ 2. What is genetics? ______________________________________________________________________ ______________________________________________________________________ 3. What information can we get from a footprint? ______________________________________________________________________ ______________________________________________________________________ 4. What is keratin and how does it help scientists solve a crime? ______________________________________________________________________ ______________________________________________________________________ 5. What is the advantage of having scientists and investigators work together to solve crimes? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________

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List of Readings

Reading In The

Content Area

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SCIENCE 21: Science For The 21st Century Interactions in the Environment — Energy Transfer


The Laws of Conservation of Energy and Mass… pg. 167 Physical and Chemical Properties……………….. pg. 171 How Venus Flytraps Work………………………. pg. 175 The Flow of Energy……………………………… pg. 179 The Wonders of Photosynthesis…………………. pg. 183 Weather Makers………………………………….. pg. 187 The Corpse Flower………………………………. pg. 189 Difficult Choices: The “Snail Saga”…………….. pg. 195


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The Laws of Conservation of Energy and Mass Energy is constantly changing from one form to another as things change around us. The Law of Conservation of Energy tells us that energy can neither be created nor destroyed. Energy can only change its form. Energy may be in the form of heat, light, electrical energy or chemical energy. Even in a chemical reaction, energy is conserved and the energy before the reaction equals the energy after the reaction. Heat energy is involved in all chemical reactions. It is either released or absorbed (taken in) during a chemical reaction. In some chemical reactions, the temperature of the environment (surroundings) goes up and this is evidence that heat has been released. Energy has not been created, however; it is just that some of the chemical energy stored in the reactants has been transformed into heat energy. Sometimes, the temperature of the surroundings goes down during a chemical reaction. This means that heat was needed by the reaction and it was absorbed from the surroundings. It was not destroyed, but rather it was converted into chemical energy of the products. For example, when wood is burned, some of the stored chemical energy is converted into heat, and light! But copper sulfate hydrate needs heat to react. If it is heated, it breaks down into copper sulfate and water. Light can also provide the energy needed for a chemical reaction to occur, instead of heat. Photosynthesis is an example of a chemical reaction in which light energy is absorbed, by green plants. (See the article, “The Wonders of Photosynthesis”) In this process, plants use energy from the sun (they take in light energy) to convert carbon dioxide and water into glucose (a sugar) and oxygen. Light energy has not been destroyed; it has been transformed into the stored chemical energy in glucose. The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction. All the mass present in substances before a chemical reaction is still present after the reaction, but in the form of new substances. The French chemist, Lavoisier, was the first person to put forth the Law of Conservation of Mass in 1785.


Name _____________________________ Date ______________________ Answer the following questions:

1. What is the Law of Conservation of Mass? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 2. What is necessary for a chemical change to take place? ______________________________________________________________________ ______________________________________________________________________ 3. What forms of energy can change in a chemical reaction? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 4. In an electrical circuit containing a battery, wires, and bulb, the chemical energy in the battery is transferred from chemical energy (in the battery) to what kind of energy? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________

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Physical and Chemical Properties

Matter is everything around you. All objects are composed of matter. If you can touch it, it is matter! Also, the planets, the sun and the stars are matter. All matter is made up of substances (pure) or mixtures of substances. Pure substances have characteristic properties which are used to describe them. Objects are different because they are made up of different substances. There are two types of characteristic properties: physical properties and chemical properties. A physical property is a characteristic property of a substance and can be observed and measured without changing the identity and composition of the substance. Physical properties include state of matter (solid, liquid, gas,) color, density, boiling point, freezing point, and melting point, solubility, etc. Chemical properties describe the way a substance changes or reacts to form new substances. These properties are only observed as one substance is chemically changed into another, during a chemical reaction. The new substances will have different composition and new properties. Some examples of chemical properties are: acidity, the ability to burn, the ability to react with water, etc. Substances can change in two ways: physical change and chemical change. Physical changes do not involve one substance changing into another. They are only changes in form, and the substances still have the same chemical composition. For example, water can change from a gas to a liquid; wood can be changed into sawdust, or a glass window can be shattered to bits.

Chemical changes occur when a substance is changed into a new substance with new characteristic properties and new composition. These changes happen during a chemical reaction. For example, colorless hydrogen gas reacts in an explosion with colorless oxygen gas to produce liquid water, or iron reacts with the oxygen in the air (in the presence of moisture) to form iron oxide, called rust. Chemical reactions change the substances in the reaction either by building up, breaking down, or rearranging existing substances.

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Name _____________________________ Date ______________________ Answer the following questions: 1. Explain the difference between physical properties and chemical properties? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 2. Give at least three examples of physical properties? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 3. Give at least three examples of chemical properties? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 4. Explain the difference between physical changes and chemical changes? Give examples? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________

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How Venus Flytraps Work

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The predator waits patiently while its prey wanders about, unaware that danger is inches away. Settling down to taste some sweet smelling sap, the unsuspecting bug makes a fatal mistake. Swiftly swinging shut, the jaws of the predator close around the bug. The struggle is brief, and soon the plant settles down to digest its tasty meal. There is actually nothing unnatural about plants that eat other creatures. Carnivorous plants have existed on this planet for thousands of years. There are more than 2500 different kinds of these plants, with appetites ranging from insects and spiders to small, one or two cell aquatic organisms. To be considered carnivorous, a plant must attract, capture, kill and digest insects or other animal life. One carnivorous plant in particular, the Venus Flytrap (Dionaea muscipula) has captured our imagination. Many people first see this amazing plant in action during their early school years and are fascinated by its strange dietary habits and unique appetite. Although the Venus Flytrap has captivated people across the world, the plant lives in an incredibly small geographic area. In the wild, they are found in a 700 mile area along the coast of North and South Carolina. Within this area, the plants live in humid, wet and sunny bogs and wetland areas. In the bogs favored by Venus Flytraps, the soil is acidic, and minerals and other nutrients are scarce. Most plants can’t survive in this environment because they cannot get enough of the building blocks needed for growth. The Venus Flytrap has the ability to thrive in this unique ecological niche by finding alternate means of getting nutrients. Living creatures like insects provide a good source of nutrients missing from the soil, and they also contain additional energy-laden carbohydrates.

Because Venus Flytraps are scarce, some early botanists doubted their existence, despite all the stories surrounding this flesh-eating plant. Most plants have some mechanism to attract animals and insects, regardless of whether or not they plan to feast on their guests. For example, non-carnivorous plants have evolved intense smells or syrupy saps to attract bees, butterflies and other insects; these bugs are then used by the plants to bring the pollen

needed to fertilize neighboring plants of the same species. In the case of the Venus Flytrap, the leaves forming the trap secrete nectar that draws in insects searching for food. When an insect lands or crawls on the trap, it is likely to run into one of six sensitive hairs on the trap’s surface. These are called trigger hairs, and they serve as a primary detector for the plant. If two of these hairs are brushed in close succession, or are touched twice, the leaves close down upon the captive insect.

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Even without a brain to analyze what it’s eating, the Venus Flytrap still manages to differentiate between insects and nonedible debris that might fall into its trap. This step is also controlled by the six sensitive trigger hairs. An insect caught inside the partially closed trap will continue to thrash about in an attempt to escape. It’s guaranteed that at least one (if not all) of the trigger hairs will be tweaked by the insect’s movement. This serves as the signal to close the trap entirely.


Name _____________________________ Date ______________________ Answer the following questions: 1. Why are some plants called carnivorous plants? ______________________________________________________________________ ______________________________________________________________________ 2. Why does the Venus Flytrap need to eat insects? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 3. What do you think would happen if you put your finger in a Venus Flytrap? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 4. Why doesn’t the plant close on inanimate objects? ______________________________________________________________________ ______________________________________________________________________ 5. Describe an environment in which you think a Venus Flytrap would not survive? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________

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The Flow of Energy

With few exceptions, all of the energy for all life and human technology comes from the sun. Animals, including humans, can’t use sunlight to produce food, but plants can do this. Plants convert the energy of sunlight into food for their own use as they grow, repair themselves, and reproduce. Plants are called producers and are at the first level in the food chain, because they provide food for all other living things. Most of the solar energy that falls on earth does not reach green plants. It bounces back to space or heats the air, oceans, and ground, and makes weather among other things. Of all the energy a plant receives from the sun, only a small amount is converted into the chemical energy that is stored in glucose, through the process of photosynthesis. Plants are eaten by consumers, which are organisms that cannot make their own food. But, when an herbivore eats a plant, it doesn’t get all the energy the plant received from the sun. This is because the herbivore may not eat all of the plant and it may not be able to digest some of what it does eat. Also, it uses some of the energy for eating, breathing, walking and staying warm. This energy eventually leaves their bodies in the form of heat energy and this form of energy is no longer useful energy in the food chain. However, a small amount of the energy is used for growth and this stored energy remains in the herbivore’s body. This energy can be used by a carnivore that eats the herbivore (secondary consumer). So, only a very small amount of the plant’s original energy stays in the food chain, to be stored eventually by the secondary consumer. As energy flows through the food chain, most of it is either used or lost to the environment as heat, so there is a limit to the number of organisms at each level of the food chain. That’s the main reason there aren’t many big fierce predators compared to the number of herbivores and why there must be lots more plants than herbivores. Without the continuous input of solar energy and new plants always growing, the whole amazing system would quickly run out of energy and everything alive would come to a “dead” stop.

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Name _____________________________ Date ______________________ Answer the following questions: 1. Why aren’t there as many large predators compared to herbivores? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 2. What happens to most of the energy from the sun that falls on Earth? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 3. What happens to most of the energy consumed by herbivores? ______________________________________________________________________ ______________________________________________________________________ _______________________________________________________________________ 4. Why is the sun considered essential for all of life? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________

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The Wonders of Photosynthesis Energy flows through the food chain from life form to life form, as plants are eaten by herbivores and herbivores are eaten by carnivores. The original source of the energy is sunlight and the first step is photosynthesis, in which the sun’s energy is turned into food by green plants. The food produced is carbohydrate molecules and they are used by all living things for energy, and as building blocks for more pieces of themselves. Almost every green surface on a plant is full of cells that are working away at making sugar while the sun is shining. The process is very complicated with many steps, but the basics are very simple. In the process of photosynthesis, plants take carbon dioxide molecules (CO2) from the air, water molecules (H2O) from the plant’s water supply, and convert them into glucose (sugar) and oxygen gas, using energy from the sun. Glucose is the carbohydrate that is the base of the food pyramid to support all life. It has been estimated that 100 billion tons of sugar (sugar is a simple carbohydrate) are made every year by green plants, marine algae, and certain kinds of bacteria. That is equal to the weight of 666 million blue whales. Glucose and other sugars have the stored chemical energy that provides the energy needed by all living things. How does this happen? All cells, even plant cells, convert the stored energy in glucose into work and heat in a process called cellular respiration (not breathing). In this process, glucose is combined with oxygen to form carbon dioxide and water vapor and this reaction releases the energy. Respiration takes place in our bodies, and in the cells of all living things, including plants, all the time. Also, glucose (sugar) is a building block out of which the cells of our bodies and the bodies of all living things are made.

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Where does the oxygen that is needed for respiration come from? Photosynthesis! So, green plants provide both the stored chemical energy (in glucose) and the oxygen gas that all living things need to live, grow and reproduce. While you are sitting and reading, every cell in your body is busy burning sugar to provide the energy to think, breathe, digest food, pump blood, stay warm and say things like: WOW, this is interesting”.

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Name _____________________________ Date ______________________ Answer the following questions: 1. What do plants turn the sun’s energy into? ______________________________________________________________________ 2. Why are carbohydrates important? ______________________________________________________________________ ______________________________________________________________________ 3. What three ingredients are necessary for photosynthesis? ________________ _________________________ _______________________ 4. What do you think happens to the oxygen that is released as a result of photosynthesis? ______________________________________________________________________ 5. Why are plants necessary for all of life? ______________________________________________________________________ ______________________________________________________________________ 6. When during the day do you think respiration occurs in plants? ______________________________________________________________________ ______________________________________________________________________

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Weather Makers The sun is the source of energy that determines our weather. When this energy reaches the Earth, it warms the Earth’s surface. However, this warming is uneven, with some areas getting more heat than others. This uneven heating makes air move from one area to another (moving air is wind) and drives the water cycle. With wind and water, all our weather is created. When air heats up, the molecules in air have more kinetic energy and move faster and faster. They have more energy to pull away from each other, spreading out and causing the air to expand. As a result, there are fewer molecules in the same amount of space (volume). The air in that space weighs less than it did when it was cooler and it exerts less pressure on the Earth. This warm air mass is called a “low” or low pressure area. Cold air molecules are packed closer together, so cold air weighs more for a given space (volume) and exerts more pressure, or “high” pressure, on the Earth. Low pressure usually signals changing or poor weather conditions, while high pressure is usually associated with clear skies. Since warm or low pressure air weighs less for a given volume than cold or high pressure air, it is less dense than cold air. The denser cold air sinks and displaces the warm air, which then rises. Once the colder air reaches the surface of the earth it spreads out. If a high and a low pressure area are close to each other a strong wind will develop, because air moves from an area of high pressure to one of low pressure. Since the equator is constantly hot and the poles are constantly cold, there is a general pattern to air circulation with the colder polar air moving toward the equator and displacing the hot equator air, and spreading out, so winds would generally blow from the poles (cold, high pressure) to the equator (warm, low pressure. But, it is more complicated than that, because the earth is rotating on its axis and gives added motion to the air masses. The four ingredients: the sun’s energy, the uneven heating of the earth, the falling and rising of air masses, and the movement of water from the earth to the atmosphere and back (evaporation and precipitation) work together to create our weather.

Wind direction and areas of high and low pressure 187


Name _____________________________ Date ______________________ Answer the following questions: 1. What happens to air when it is heated? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 2. Which do you think brings us clear skies- high or low pressure? Explain. ______________________________________________________________________ ______________________________________________________________________ 3. Why does heated air exert less pressure on earth? ______________________________________________________________________ ______________________________________________________________________ 4. How does the rotation of the earth affect the direction of the air flow? ______________________________________________________________________ ______________________________________________________________________ 5. What are the four weather makers? ______________________________________________________________________ ______________________________________________________________________

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The Corpse Flower

The Rafflesia, also known as the corpse flower, has been used on tourist brochures, commemorated on stamps, and featured on coins. What makes this flower so special?

The species Rafflesia Arnoldi, is the world’s largest single flower. It was discovered in 1818, in the Indonesian rain forest by Sir Thomas Stanford Raffles and Dr. Joseph Arnold. This flower has no leaves and hardly any stem, just a huge speckled five-petaled flower with a diameter up to one meter. The flower can weigh up to 10 kilograms (about 25 pounds)! The flower smells like rotting meat, hence its common name translates to “corpse flower.” It is also referred to as one of the “ monsters of the plant kingdom.”

The Rafflesia is really a parasite. It grows within its host (a vine) and is no more than a tangle of fibers. The flowers of Rafflesia take a long time to develop. From the first visible inception of a flowing bud, it may take up to ten months for the flower to bloom. The flowering lasts no more than a couple of days. Once the flowers are in bloom, no one is really sure how the flowers are pollinated or how the seeds are dispersed. One botanist suggests that termites help pollinate the plant and elephants while eating and stepping on the termites, aid in to spread the seeds.

Rafflesia is known to be found only in the rainforests of Malay Peninsula, Sumatra, Borneo and the Philippines. These countries have made a concerted effort to protect these flowers. Areas where the Rafflesia grows have been designated as protected areas.

Rafflesia

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Name _____________________________ Date ______________________ Answer the following questions:

1. How did this flower get its name? ______________________________________________________________________

2. Why is it called a “corpse flower?” ______________________________________________________________________

3. A person who studies plants is called? ______________________________________________________________________

4. Why does this flower grow only in the rainforest? ______________________________________________________________________ ______________________________________________________________________

5. Why would governments want to protect the Rafflesia? ______________________________________________________________________ ______________________________________________________________________ 6. If you could “invent” a really interesting plant, describe how it would look and its environment. ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 193

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Difficult Choices: The “Snail Saga”

For several years first graders who use SCIENCE 21 have enjoyed studying snails as a part of the program. The developers of SCIENCE 21 tried to identify animal species for kids to study that represented various major types of living things. For example, kindergarteners study newts (which are amphibians); first graders work with snails (which are mollusks); second graders study crayfish or triops; third graders work with butterflies (which are insects); and so on. The snail unit is a really interesting one. Maybe you remember it? Students identified the main parts of the snail's body and studied the snail’s response to different environmental conditions. It was fun and great learning. In 2002, the United States Department of Agriculture (USDA) decided that the species of land snails that we had been using for many years would no longer be allowed in New York State schools. Snails are considered "agricultural pests" and in some places they have multiplied rapidly, eaten crops, and left slime trails that if left on walkways could present a trip hazard. Our supplier of snails provided a substitute, a species of aquatic or pond snails, but no one was happy with this new type of snails. They were very small and the kids studying them could not witness their activity and responses. We appealed to the USDA asking them to allow us to use the larger, land snails, which we had used in the past. We even proposed to have the snails returned to the supplier (along with the gravel and soil that they live in) so that we could make sure that snails would not be released into the local environment. The USDA responded that they could not take a chance that some snails might get out of classrooms, lay eggs, and then cause a problem for New York State farmers because the snails might escape from the classroom tanks and then if they multiply in large quantities, eat their crops.

The USDA developed a list of snails species that are native to New York. This means that these snails could be used because their "natural home" is in New York and they do not represent a threat to local farmers. We worked with our supplier to try to get enough "native New York snails." Two men spent a weekend looking for these "New York snails" in their natural environment, but they were only able to find 17 snails. If we tried to raise these snails in a laboratory it would take many years before we could get enough

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snails for SCIENCE 21 classrooms. (Currently, we use about 11,000 snails for all of the SCIENCE 21 schools.) We asked the USDA if we could use the old species of snails for another year or two until we could raise a sufficient quantity of "New York snails" to fill our needs. Their response was “No.” In this situation, there are people, all who care about children and their education who disagree about this issue. Some people feel that the risk is not too great to use the kinds of snails that we had used for many years until we can raise a sufficient quantity of "New York snails." The folks at the USDA feel that the risk of using these snails (and having them multiply) in New York, which is not their natural home, is too great-- that the risk to the plant growers does not outweigh the educational benefit. What do you think?


Name _____________________________ Date ______________________ Answer the following questions: 1. What do you think? Should the program developers at SCIENCE 21 continue to ask for the use of land snails or should they agree that the risk to local farming is too great? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 2. Why do you think the USDA is sensitive to the issue of introducing non-native species into a local environment? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ 3. Which view do you take? Is the value of using land snails for student activities more important than the chance of releasing non-native snails into the local environment? ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________

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Grade 5 RCA - Wappingers Central School District · foot race? A good scientist ... When you drop...

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