Grade Five
SCIENCE 21: Science For The 21st Century
Interactions of Chemical Matter
GRADE 5 • UNIT 1 • READING IN THE CONTENT AREA
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
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
87
Reading In
The
Content Area
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:
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
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.
89
Grade 5, Unit 1, Reading in the Content Area
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.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
91
Grade 5, Unit 1, Reading in the Content Area
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.
93
Grade 5, Unit 1, Reading in the Content Area
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?
____________________________________________________________________
____________________________________________________________________
__________________________________________________________________________________
95
Grade 5, Unit 1, Reading in the Content Area
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.
97
Grade 5, Unit 1, Reading in the Content Area
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?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
99
Grade 5, Unit 1, Reading in the Content Area
“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.
101
Grade 5, Unit 1, Reading in the Content Area
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?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
103
Grade 5, Unit 1, Reading in the Content Area
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.
105
(over)
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.
106
Grade 5, Unit 1, Reading in the Content Area
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?
____________________________________________________________________
107
SCIENCE 21: Science For The 21st Century
Interactions in the Microworld
GRADE 5 • UNIT 2 • READING IN THE CONTENT AREA
In the Reading in the Content Area section, you will find
several readings that may be used for Unit 2. 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
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
©2004, Putnam/Northern Westchester BOCES • SCIENCE 21 • Grade 5 • Unit 2
197
Reading In
The
Content Area
Grade 5, Unit 2, Reading in the Content Area
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.
Convex Lens
Parallel
light
rays
Focal
point
Gathers light to
focal point, then
spreads the light
to make the image
larger.
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.
199
Grade 5, Unit 2, Reading in the Content Area
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?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
201
Grade 5, Unit 2, Reading in the Content Area
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.
Cell Theory Historical Timeline
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 evidence 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.
(over)
203
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.
204
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?
______________________________________________
______________________________________________
______________________________________________
205
Grade 5, Unit 2, Reading in the Content Area
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.
Muscle Tissue
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!
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Grade 5, Unit 2, Reading in the Content Area
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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Grade 5, Unit 2, Reading in the Content Area
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.
211
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?
____________________________________________________________________
____________________________________________________________________
213
Grade 5, Unit 2, Reading in the Content Area
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?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
217
SCIENCE 21: Science For The 21st Century
Interactions in the Human Body
GRADE 5 • UNIT 3 • READING IN THE CONTENT AREA
In the Reading in the Content Area section, you will find
several readings that may be used for Unit 3. 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
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
©2004, Putnam/Northern Westchester BOCES • SCIENCE 21 • Grade 5 • Unit 3
203
Reading In
The
Content Area
Grade 5, Unit 3, Reading in the Content Area
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.
205
Grade 5, Unit 3, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
207
Grade 5, Unit 3, Reading in the Content Area
The Heart in History
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.
209
Grade 5, Unit 3, Reading in the Content Area
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?
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
211
Grade 5, Unit 3, Reading in the Content Area
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.
213
Grade 5, Unit 3, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
215
Grade 5, Unit 3, Reading in the Content Area
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.
217
Grade 5, Unit 3, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
219
Grade 5, Unit 3, Reading in the Content Area
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.
221
Grade 5, Unit 3, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
223
SCIENCE 21: Science For The 21st Century
Interactions in the Environment — Energy Transfer
GRADE 5 • UNIT 4 • READING IN THE CONTENT AREA
In the Reading in the Content Area section, you will find
several readings that may be used for Unit 4. 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
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
©2004, Putnam/Northern Westchester BOCES • SCIENCE 21 • Grade 5 • Unit 4
165
Reading In
The
Content Area
Grade 5, Unit 4, Reading in the Content Area
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.
167
Grade 5, Unit 4, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
169
Grade 5, Unit 4, Reading in the Content Area
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.
171
Grade 5, Unit 4, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
173
Grade 5, Unit 4, Reading in the Content Area
How Venus Flytraps Work
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.
175
(over)
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.
176
Grade 5, Unit 4, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
177
Grade 5, Unit 4, Reading in the Content Area
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.
179
Grade 5, Unit 4, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
181
Grade 5, Unit 4, Reading in the Content Area
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.
(over)
183
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”.
184
Grade 5, Unit 4, Reading in the Content Area
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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Grade 5, Unit 4, Reading in the Content Area
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
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Grade 5, Unit 4, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
189
Grade 5, Unit 4, Reading in the Content Area
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
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.
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Grade 5, Unit 4, Reading in the Content Area
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
Grade 5, Unit 4, Reading in the Content Area
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
(over)
195
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?
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Grade 5, Unit 4, Reading in the Content Area
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?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
197