Author: Maddie Van Beek

Fingerprints
Take a close look at your fingertips.  All those swirly marks in your skin are your fingerprints, and yours are incredibly unique. Did you know that just like snowflakes, no two fingerprints are alike? 

Fingerprints are just one tool used in a field called forensic science. Forensic science is the science of gathering information about past events, and using that information in a court of law. When investigators are trying to determine who committed a crime, they use forensic science! Crime scene investigators often use fingerprints to help catch the criminal. 

Play the Whodunit game to learn more about fingerprint types and solve a crime scene! ​

Now that you’ve played the Whodunit game, you should know that there are THREE types of fingerprints: Loop, Arch, and Whorl. ​

Take your own fingerprints! 

What kind of fingerprint do you have? 

YOU WILL NEED:

Paper

Pen

Ink pad

YOU WILL DO:

1. Draw 10 boxes on a white piece of paper.

2. Label each box for each finger (Left Pinky, Left Ring, Left Middle, etc.)

3. Press your right thumb on an open ink pad. Make sure you start with your thumb tilted to the left and then roll to the right so that the whole pad of your thumb is covered in ink.

4. Press your right thumb on the box labeled “Right Thumb” and roll your finger just like you did to apply the ink. 

5. Repeat this for each finger on your right hand, and then your left hand. 

6. Analyze your prints! Are you Loop, Arch, or Whorl? 

Fingerprints are just one way that our bodies are uniquely different from one another! ​

DNA Project Key

Body: 

Pink = Medium, short and stocky

Yellow = Tall and lean

Orange = Tall and muscular

Green = Small and thin


Ears:

Pink = Pointed

Yellow = Large and floppy

Orange = Medium square

Green = Medium and floppy

Nose: 

Pink = Pink/Red

Yellow = Black

Orange = Brown

Green = Spotted

Snout:

Pink = Long and thin

Yellow = Short and smushed

Orange = Droopy jowls

Green = Medium and square

Eyes:

Pink = Blue

Yellow = Brown

Orange = Grey

Green = Green

Coat Color:

Pink = Brown

Yellow = Black

Orange = Spotted

Green = White

Fur: 

Pink = Short and Curly

Yellow = Short and course

Orange = Long and shaggy

Green = Long and curly 

Tail: 

Pink = Long and lean

Yellow = Short and stubby

Orange = Medium

Green = Curly 

Legs:

Pink = Short and stubby

Yellow = Long and lean

Orange = Medium

Green = Muscular

References:
​

• http://learn.genetics.utah.edu/content/inheritance/activities/pdfs/A%20Recipe%20for%20Traits_Public.pdf
• http://www.pbs.org/wgbh/amex/dillinger/sfeature/sf_whodunit.html
• http://www.slideshare.net/MrsTabor/dna-for-7th-grade
• http://www.chem4kids.com/files/bio_dna.html
• http://tfscientist.hubpages.com/hub/explaining-dna-to-a-six-year-old

Image Credits:

Image 1: Fingerprint arch. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/c/c5/Fingerprint_Arch.jpg Image was created by the United States Department of Commerce and is in the Public Domain. 

Image 2: Fingerprint loop. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/0/06/Fingerprint_Loop.jpg Image was created by the United States Department of Commerce and is in the Public Domain. 

Image 3: Fingerprint whorl. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/4/49/Fingerprint_Whorl.jpg Image was created by the United States Department of Commerce and is in the Public Domain. 

Image 4: Shaffee, 2015. Autosomal recessive - mini. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Autosomal_recessive_-_mini.svg/800px-Autosomal_recessive_-_mini.svg.png File used in accordance with the Creative Commons Attribution-Share Alike 4.0 International license.

Image 5: Lynch, 2011. Snow flakes. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/2/23/Snow_Flakes.jpg/800px-Snow_Flakes.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license.

Image 6: 1936. Joy Oil gas station blueprints. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/5/5e/Joy_Oil_gas_station_blueprints.jpg/1024px-Joy_Oil_gas_station_blueprints.jpg File is in the Public Domain. 

Image 7: Zaldua, Equisoain, Zabalza, Gonzalez & Marzo, 2016. Cell animal. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/9/9e/Cell_animal.jpg File used in accordance with the Creative Commons Attribution-Share Alike 4.0 International license.

Image 8: Madprime, 2016. DNA chemical structure. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/e/e4/DNA_chemical_structure.svg/800px-DNA_chemical_structure.svg.png File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license.

Image 9: Zephyris, 2009. DNA orbit animated static thumb. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/d/db/DNA_orbit_animated_static_thumb.png  File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license.

Image 10: Skovgaard, 2007. Boxer puppy fawn portrai. Uploaded from Wikimedia Commons on 7/17/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/5/53/Boxer_puppy_fawn_portrai.jpg/1024px-Boxer_puppy_fawn_portrai.jpg File used in accordance with the Creative Commons Attribution 2.0 Generic license. 

Author: Maddie Van Beek

I’m sure you know that we all have five senses: Taste, touch, smell, hearing, and sight. Even though the senses of taste and smell are separate, they are so close to one another that they are intertwined. Taste and smell work together to help you fully experience food. 

Activity: In the following activity, you will see why it is difficult to determine similar foods when you lose your senses of sight and smell. 



YOU WILL NEED:

• Potato
• Apple
• Knife
• An assistant
• Glass of water

Here’s what to do!

1. Peel the potato and the apple.
2. Cut a small piece of apple and a small piece of potato. Make sure they are the same shape and size. 
3. Have your assistant tie the blindfold around your head so you cannot see. Have your assistant hand you a piece of potato or apple, but do not have them tell you what it is. 
4. Hold your nose so that you cannot breathe out your nostrils and eat the first piece. Make sure you hold your nose the entire time you are chewing and swallowing. Take a drink of water to clear any remaining taste out. 
5. Hold your nose and eat the second piece. 
6. Take your guess... which was the apple and which was the potato? 
7. Part of what made this so difficult to discern the difference was that the texture of the potato and the apple are so similar. What other food items could you compare? Make sure you choose items that similar in texture AND category of taste (sweet, sour, bitter, salty). 
8. For example, you could use:
1. ketchup vs. steak sauce
2. juice vs. kool-aid
3. chocolate pudding vs. vanilla pudding
4. lime jello vs. cherry jello
5. carrot vs. broccoli stalk 

Another way you could do this is to mix water with other flavorings to represent salty, sweet, bitter, and sour. For example, you could create salt water, sugar water, lemon water, and coffee. Have your participants close their eyes and see if they can identify each drink. Record your observations. 




References: 

https://faculty.washington.edu/chudler/chtaste.html

http://www.sciencekids.co.nz/experiments/smelltaste.html

http://www.brainfacts.org/sensing-thinking-behaving/senses-and-perception/articles/2012/taste-and-smell/

http://www.innerbody.com/image/nerv12.html

Author: Maddie Van Beek

Did you know that April 22nd was Earth Day? Earth Day began back in 1970 as a response to a devastating oil spill.  Now, Earth Day continues to remind people to take care of and celebrate our Earth! People often memorialize earth day by volunteering, planting a garden, cleaning up highways, among many more ways to leave our earth better than we found it. What can you do to help your world? 

The important thing to remember is to take care of our world not just on Earth Day, but every day! What are some ways that you can take care of the earth in your community? 



Here’s some more information about Earth Day and the different ways you can celebrate it!

In relation to Earth Day, we are going to learn what the word biodegradable means. 




Have you ever seen this symbol? If you do, that means the item is biodegradable! But what exactly does that mean? 

Biodegradable is defined as any item that can be decomposed (broken down) by bacteria or other living organisms. Think about what this means. What items can you think of that might be biodegradable? For example, a peanut butter and jelly sandwich is biodegradable! You, a living organism, break down that sandwich in your body when you eat it. 



Biodegradable material is usually organic material that was originally from other living organisms. The word organic can have a few different meanings, but in this case, it means plant or animal matter. This not only includes plants and animals, but plant and animal waste material, as well. 



While much of the world around us is biodegradable, some materials are not. When non-biodegradable items are littered around, they don’t break down like biodegradable material. For example, a plastic bag can take up to 20 years to break down! These items then end up in landfills, cluttering our earth and potentially causing harm to animals and their habitats. 



Just imagine how long the plastic in this landfill would take to decompose!

This is just one example of an animal affected by littered plastic. 

How DOES plastic decompose, anyway? Find out HERE. 

Activity

YOU WILL NEED:

Dirt

Water

Deep pan or garden box

Popsicle sticks

Various items to plant. May include:

• Dirty sock
• Apple core
• Banana peel
• A kleenex
• Milk carton
• Plastic wrapper
• Piece of bread
• Toilet paper

Here’s what to do! 



You are going to plant your various items in your garden. Instead of planting seeds and watching things grow, you are going to observe how the items decompose. Essentially, you are creating a reverse garden! Through this experiment, you are going to find out which items are biodegradable and which are not. 



1. Make predictions! Write down which items you think will decompose the fastest, slowest, or not at all. Make guesses on how long you think each will take to decompose. 

2. Fill the deep pan with dirt. 

3. Use a pen or marker to label popsicle sticks with each item you are going to plant. 

4. Plant each item in the pan. Make sure the items are completely covered in dirt and are planted at the same depth. You could use a ruler to measure from the item to the surface of the dirt to make sure the items are all covered by the same amount of dirt. 

5. As you plant each item, stick the labeled popsicle stick into the dirt behind the item so you can identify the items later on. 


6. Water your garden! 


7. Now, the waiting game has started. Make sure you water your garden once a day. After one week, dig up your garden and make observations. What do your items look like now? Take pictures or make sketches in your observation journal. Which items seem to be decomposing the fastest? Are there any items that look the same?


8. Rebury your items as you did in step 4 and continue with daily watering. 


9. Check back at week 2 and take pictures, make sketches, and record observations in your journal. Rebury and continue watering. 


10. Repeat steps 7 and 8 for two more weeks. 


11. At week 4, dig up your items and record your final observations. 



Remember, those items that didn’t decompose wouldn’t break down for many years to come! Use this activity as a great reminder to take care of our beautiful earth! 




References: 

• http://lifestyle.howstuffworks.com/crafts/seasonal/winter/science-experiments-for-kids3.htm
• http://en.wikipedia.org/wiki/Biodegradation
• http://www.earthday.org/earth-day-history-movement
• http://des.nh.gov/organization/divisions/water/wmb/coastal/trash/documents/marine_debris.pdf

Author: Maddie Van Beek

We all know that trees and plants make our world prettier and provide us with fruits and vegetables. But did you know that we actually NEED plants to live? Through the process of photosynthesis, plants take in the carbon dioxide that we give off and convert it to the oxygen that we desperately need to survive! How does this whole process work? 




This diagram explains the basic components of photosynthesis: 

Plants not only need carbon dioxide, but also use water and sunlight to complete the photosynthesis process. 




Check out our blog on xylem to understand how water gets from the ground to the leaves of a plant:

Photosynthesis reaction equation:

This catchy song will help you remember the basics of photosynthesis!

Follow-up questions: 

• What happens during photosynthesis? 
• How is chlorophyll involved in photosynthesis? 
• What do xylem do? 

Try defining this important vocabulary in your own words: 

• Chloroplasts
• Chlorophyll
• Photosynthesis
• Xylem

You now know everything you need to complete our basic photosynthesis experiment, but if you want to learn EVEN MORE, watch the video below!




This video explains the complexities of photosynthesis! You’ll know more than you ever wanted to know about how photosynthesis works. 

Activity



YOU WILL NEED:

• Spinach leaves
• Hole punch
• Tweezers
• 10cc syringe (no needle)
• Water
• Baking Soda
• Soap

Here’s what to do!



If you like visual instruction, watch this video to see how to complete the experiment: 

1. First, you need to create your bicarbonate solution. Do this by combining 1/8 teaspoon of baking soda with 1 and 1/4 cups of water. Stir the baking soda in until it is completely dissolved. 
2. Next, use the hole punch to punch holes in your spinach leaves until you have about 20 spinach leaf discs. 
3. Remove the plunger from the syringe, and place the spinach discs into the syringe. 
4. Use the tweezers to push the discs down as far as they can go. Be careful not to crush or damage them. 
5. Once you have all the leaf discs in the syringe, replace the plunger. 
6. Put the tip of the syringe in the bicarbonate solution and pull back the plunger to suck up 10ccs of the solution. The baking soda solution is a source of bicarbonate ions, which is one source of carbon dioxide for photosynthesis.  
7. Cover the end of the syringe with your finger, and then pull the plunger upwards as far as it can go to pull the air out of the leaf discs. Alternate pulling the plunger out and pushing it down (remember to keep the end covered with your finger the whole time to create a vacuum). Pushing the plunger down is forcing the bicarbonate into the leaf discs and pulling it up will remove any air from spaces in the leaves.
8. Continue to do this until you see the leaf discs start to sink. Once all your leaf discs have sunk, squirt out the baking soda solution into a sink, making sure not to allow the leaf disks to plug the syringe.
9. If you have trouble getting your leaf discs to sink, you can add a small drop of soap to the bicarbonate solution and try again. The soap makes the leaf less hydrophobic and will help it more easily absorb the solution.  
10. Next, add more baking soda solution. You should suck up about 10 ccs, as you did in step 6.  Swirl your syringe around to make sure the leaf discs aren’t stuck to the sides or to each other. 
11. Place your syringe upright in a well-lit area. Either artificial or natural light will work. 
12. Wait to see how long it takes for the leaf discs to float. Record the time when the first disc rose to the surface. Wait until at least 5 leaf discs have risen back to the surface. Record the time it took for 5 leaf discs to float. If you are patient enough, record the time that it takes for all your leaf discs to float. What’s the point of this? You just watched photosynthesis occur!  The oxygen created inside the leaves by photosynthesis is making the leaves float again.  
13. Practice making graphs! Create a line graph to show how long it took for the discs to float. I would put time along the x-axis and number of leaf discs along the y-axis. You could do this by hand, or you could use Excel to create it electronically. If you need help using Excel, refer to our blog on heart health for instructions. 

Follow-up questions:

1. Would this experiment have worked with normal tap water? Why or why not?
2. What was happening when the leaf discs sunk?
3. Why did the leaf discs float at the end? 
4. Create a diagram to show the steps of your experiment and how it relates to photosynthesis. 

If you had fun learning about photosynthesis, you might also like our blog on plant transpiration.



References:

• <iframe width="560" height="315" src="https://www.youtube.com/embed/XV9FOWleErA" frameborder="0" allowfullscreen></iframe>
• https://blog.udemy.com/photosynthesis-experiment/

In nearly every household around the world, it is not unusual to go to the cupboard now and then and see a sight like this one:

Most people are a little disgusted when they see this, some are fascinated, and virtually nobody finds it appetizing!  But what exactly is it?

The fuzzy green carpet that appears to be covering your bread, fruit, or vegetables when they’ve been around just a bit too long is called mold.  Molds are a type of fungus, a microorganism—that is, a tiny living thing—made up of multiple cells growing in long strands called hyphae.  The fuzzy mass that the hyphae create is called the mycelium.

Molds may not be very appetizing—you should throw away food that you see is growing mold—but they are very important!  They perform very important functions as decomposers of litter, in production of some of our food, and even in medicine! 

Molds as Decomposers

As living things are born, grow, and eventually die, something must happen to the waste produced by these living things, as well as to their bodies when they die.  Molds are partially responsible for the breakdown and digestion of this litter, and so they facilitate the return of the nutrients contained within these living things back to the soil.  If molds and other microorganisms could not do this, the nutrients contained in the bodies of dead plants and animals would remain there forever, and the soil would never get them back, making it impossible for new plants to grow, and new animals to be fed.

Molds in food production

Molds are traditionally used in the production of a variety of different foods, such as soy sauce, cheese, and salami.  The molds break down the sugars and starches of the soy and milk, allowing them to ferment (a process which turns sugars into acids, alcohols, and gasses), which improves the nutrition, flavor, and/or shelf life.

Molds making medicines

One of the most important discoveries of the 20th century was the discovery of penicillin, one of the first antibiotic drugs to be used widely, and which was of great importance during World War II (see Reference 3 for more information).  Penicillin is produced by a group of molds called Penicillium, and is still used today. 

Another medicine that is produced by molds includes the immune suppressing drug called cyclosporine, which is used to prevent patients’ bodies from rejecting newly transplanted organs (like lungs or hearts).  Cyclosporine is produced by the mold Tolypocladium inflatum, originally found in Norwegian soil.  Several cholesterol lowering drugs are also made by molds. 

While most molds are not dangerous to the average person, if enough mold is present in the surroundings it can make you sick.  There are also some types of mold that are extremely dangerous, producing toxic compounds that can cause nerve damage and even death.  These are not present everywhere, but it is always best to be safe, and avoid exposure to homes or other buildings with lots of mold growth. 

GROW A PET MOLD!

Here’s what you’ll need:

1.       A piece of bread, preferably homemade or from a local bakery

2.       A zip top bag

3.       A pair of scissors

4.       A warm, dark cupboard that is NOT used to store food

Here’s what you need to do:

1.       Place your piece of bread inside the zip top bag, and close it carefully

2.       Cut a few very small slits in the bag to allow air circulation

3.       Place the bag in the cupboard, and make sure no one eats the bread!

4.       Allow the bread to rest undisturbed for at least a few days, then up to a few weeks, checking it daily. 

What did the bread look like after two or three days?  After one week?  After two weeks?  Write down everything you observe in your journal, and take pictures of the bread every few days if you can; pictures are a great way to record changes!

References for further reading:

1.       “Mold.”  Wikipedia.  September 12, 2014.  Viewed on 9/16/14.  http://en.wikipedia.org/wiki/Mold#Pharmaceuticals_from_molds

2.       Campbell, N.A.; Reece, J. B.; Mitchell, L. G.  Biology, 5th ed (1999). Addison Wesley Longman, Inc.  Menlo Park, CA. 

3.       “Penicillin.”  Wikipedia.  September 16, 2014.  Viewed on 9/16/14.   http://en.wikipedia.org/wiki/Penicillin#History

4.       “Tolypocladium inflatum.”  Wikipedia.  July 29, 2014.  Viewed on 9/16/14.  http://en.wikipedia.org/wiki/Tolypocladium_inflatum



Image licenses:

GNU Free Documentation License

Creative Commons Attribution-Share Alike 3.0 Unported license.

Creative Commons Attribution 2.0 Generic license.

We know living things are made of cells, and that nearly all living things are about 70% water.  But how does a living thing absorb water?  Each cell of a living organism is completely enclosed by the cell membrane...how can water get in and out?

The answer is osmosis!  Osmosis is the passing of a solvent (usually water) through a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration, generally until the solute concentrations on both sides of the membrane are approximately equal.  To understand this fully, we must understand both what solvents and solutes are, and what semi-permeability means.

A solvent is a substance, usually a liquid, in which solutes may be dissolved.  In the case of cells, this is water.  Other common solvents you may be familiar with include alcohol, acetone (commonly found in nail polish remover), and even air—remember gasses can be solutes also!

A solute is any substance dissolved in a solvent.  In a cell there are many solutes, such as salts, sugars, and other small molecules.  Simply put, a solute is the substance that is dissolved, and the solvent is the substance that does the dissolving.

A semi-permeable membrane is a thin, selective barrier that only allows certain things to pass through it, while keeping other things on one side or the other.  We see semi-permeable membranes very frequently in biology—nearly every living thing has them not only as the outer membrane of their cells, but also as part of the organelles within their cells.  These biological membranes allow water to pass through, without allowing most solutes to pass. 

A very good example of osmosis in action is what happens when we put red blood cells into solutions with different amounts of solute.  These different solutions may have more solute (hypertonic), less solute (hypotonic), or equal amounts of solute (isotonic) as compared to the red blood cells. 

Put the red blood cells in a hypertonic solution, and water will flow through the membrane out of the cells, since there is a higher solute concentration on the outside of the cells.  As a result, the cells will become wrinkled and shriveled up!

Put the cells in a hypotonic solution, and water will flow through the membrane into the cells, since there is now a higher solute concentration on the inside of the cells.  As a result, the cells will become very full and bulge, and may even burst!

If we put the cells in an isotonic solution, the solute concentration is now balanced between the inside and the outside of the cells, allowing them to maintain their normal shape. 

TRY THIS!

A good model of a cell is a typical chicken egg—it has a shell on the outside, but remove that hard shell and it also has a semi-permeable membrane on the outside! 

After you remove the shell using vinegar, you can do some pretty interesting things with your egg!

Here’s what you’ll need:

1.       Two eggs (extras are appropriate, just in case!)

2.       Two cups of vinegar

3.       One 3-4 cup clear plastic cup or bowl

4.       One large slotted spoon

5.       Two small, wide mouthed drinking glasses

6.       One cup of pure distilled water

7.       One cup of corn syrup


NOTE:  This experiment requires some planning ahead; preparing the eggs will take 24 to 48 hours.

Here’s what to do:

1.       Place your eggs in the clear plastic cup.

2.       Pour the vinegar over the top of the eggs.

3.       Wait 24-48 hours for the vinegar to dissolve the egg shells!  Look closely at the shells as they are dissolving in the vinegar—you should see small bubbles forming on the shell.

4.       When the egg shells are fully dissolved, carefully remove them from the vinegar with the slotted spoon.  Place one egg in each of the two drinking glasses.

5.       Pour one cup of corn syrup over one of the eggs.

6.       Pour one cup of distilled water over the other egg.

7.       Allow the eggs to sit at room temperature for 3 hours to overnight.

8.       Remove the eggs from their glasses with the slotted spoon, and place them carefully on the table.

What do the eggs look like?  Has their appearance changed?  If so, how?  Based on this observation, which of these solutions is hypertonic?  Hypotonic?  Sketch the way the eggs look, and be sure to write down all your observations!



Image Licenses:
Creative Commons Attribution-Share Alike 3.0 Unported license.

Everywhere you look there are different kinds of plants.  The grass on your lawn, the trees and flowers in the park, and the vegetables in your garden or on your plate are all plants.  Plants are incredibly varied and diverse; recent information says there are almost three hundred thousand species of plants on Earth (This information comes from Science Daily.  To learn more go to www.sciencedaily.com)! Of course we know that plants are alive, but they are also very different from us.  For instance, we know plants grow from seeds, but how does the plant go from a seed to the leafy green that we see?  How is a plant born? 

Nearly every plant you see around you, from the blades of grass to the largest trees, came from a seed.  When a plant reproduces (that is, when it has its babies), it puts them in a hard capsule along with enough food for them to live on and grow until they can start making food for themselves.  Now, the seeds from different types of plants are also very different from each other; some seeds are as tiny as the head of a pin, and some are as large as a grown man’s fist—the largest seed in the world is from a palm tree called the Coco de Mer, is 15-20 inches in diameter, and can weigh up to 60 pounds!  However, every seed no matter its size has to have three things: 1) the baby plant, called the embryo; 2) a food source for the embryo to use until it can make its own food (this is sometimes called the endosperm, or sometimes the cotyledons, depending on the type of seed); and 3) a hard shell to protect the embryo, called the seed coat.  If we could look inside your bean seeds, we would see these things.

When the embryo is inside the seed it is dormant, meaning asleep, and is not growing.  Being in this state of deep sleep is good for the embryo; it means that if conditions in the environment are not good for the plant to grow, it can stay dormant inside its seed until the conditions are right.  For our seeds, that means they need water (which means they will be able to take up nutrients from their environment), and warmth (which means sunlight)!  Once the seed finds these conditions, the seed coat will take up water and rupture, to let the embryo out. 

The embryo will use the food in its cotyledons and begin growing. 

This process when the embryo first begins to grow and come out of its seed is called germination.  If we provide water and warmth to our seeds, we can get them to germinate for us!

Here's what you'll need:

1.     10 Bean seeds

2.     Paper towels

3.     2 small plates

4.     A journal to write down all your observations

Here's what you need to do:

1.     Take two paper towels and soak them in water. Lay them flat on a plate, one on top of the other. 

2.     Fold the soaked paper towels in half.

3.     Take five bean seeds, and place them at one end of the folded, wet paper towels.

4.     Fold the other end of the paper towels over the seeds.  Place the wet paper towels with the seeds on the plate, and keep them in a warm place (a sunny window sill would work very well). 

5.     Now take two more paper towels, and repeat the procedure from above, but this time do not get the paper towels wet!  Put these paper towels and seeds on the other plate, and keep them in the same place as the seeds in the wet paper towels.

6.     Check the seeds every day, making sure the paper towels for the first set of seeds stay wet by adding one or two tablespoons of water each day.  After 5-7 days, there should be a small white shoot coming out of the seeds in the wet paper towels.  This means they have germinated!


How long did it take your seeds to germinate?  When the seeds germinated, what did they look like?

What do the seeds in the dry paper towels look like?  Did they germinate? Why or why not?

Be sure to write down all your observations!!


MAKE UP YOUR OWN EXPERIMENT!

What else could affect the plants’ germination?  They must have water and warmth, but what about nutrients?  If you added a little sugar to the water you use to soak the paper towels, would they germinate faster?  Try the experiment again using different liquids to soak the paper towels (try sugar water, soda, coffee...be creative)!  Be sure to germinate a few seeds in water alone too, so that you have something to compare your test to.  Also remember to write down all your observations in your journal!

You probably already know plants need water to grow.  Maybe you have a garden in the summer, and have needed to water it if there wasn’t enough rain to keep the plants healthy.  We can see what happens when plants don’t get enough water during a drought—an extended period when the water supply is low.  During a drought, local crops often suffer.

Plants get the water they need from the soil in which they grow.  But how does the water move from the plant’s roots in the soil to the other parts, like the stems and leaves?   This movement of water takes place in the xylem (pronounced ZY-lum), vein-like tubes that run from the roots of the plant to the leaves and other parts.  These tubes move water and other nutrients from the soil to the parts of the plant that need them.

Think of the xylem of the plant as a little like drinking straws.  Plants naturally lose water through their leaves:  During the day, small pores called stomata open on the leaf surface of the plant letting in nutrients from the air (like carbon dioxide)..  This also allows some water to evaporate, which helps keep the plant cool, the same way your skin does when you sweat.

This evaporation of water through the stomata causes more water to be pulled upward through the xylem of the plant, similar to the way you pull water up a straw with your mouth.

We almost never get to see the xylem of the plants around us, because they are buried deep inside the plant.  But we can make them much easier to see using food coloring, and a piece of celery!

TRY THIS!

Here’s what you’ll need:

1.       6 Stalks of celery, at least 6 inches long

2.       6 Drinking glasses

3.       A 1-cup measuring cup

4.       Water

5.       Red or blue food coloring

6.       A knife (have an adult help you with this!!)

7.       A cutting board

8.       Paper towels

9.       A ruler

Here’s what to do:

1.       Cut the pieces of celery so they are all the same length.  Cut only the bottom (root) end, leaving any leaves at the top.  Try to leave the stalks as long as possible!

2.       Measure one cup of water into each of your six glasses.

3.       Put 10 drops of food coloring into each glass.

4.       Add a stalk of celery to each glass, the cut end submerged in the water. 

5.       After two hours, remove one stalk of celery, and dry it off with a paper towel.  Take a look at the bottom of the stalk that was in the water.  Do you see any color change?  Cut the stalk in half from the bottom to the top (lengthwise), and using your ruler measure how far from the bottom end the dye has traveled.  The small tubes that have changed color are the celery’s xylem!

6.       Measure the water left in the glass.  Write down how much is left.

7.       Write down all your observations, like what color the celery is changing, and how far up the celery the dye has traveled!

8.       Do this again after 4 hours, 12 hours, 24 hours, and 48 hours.  Be sure to write down any changes you see in the celery, and how far the dye has traveled each time. 

What happened to the dye?  Why do you think this happened?  Now that your experiment is done, how much water is left in the final glass?  Is this what you expected?

What else can you do with your celery?  What would happen if you changed the conditions, like putting the glasses with the celery in the sun, or in a dark cupboard?  What about if you put the glass with the celery in a re-sealable plastic bag, and sealed it up during the experiment?  Use your imagination, and try new things, but always be sure to write everything down, like what you are doing, and what you see during your experiment!

References for further reading:

1.       McElrone, A J; Choat, B; Gambetta, G A; Brodersen, C R . (2013) Water Uptake and Transport in Vascular Plants. Nature Education Knowledge 4(5):6

2.       Plants: Essential Processes, Water transport.  SparkNotes.  Retrieved 4-10-14.  http://www.sparknotes.com/biology/plants/essentialprocesses/section1.rhtml

Licenses:

Creative Commons Attribution-Share Alike 3.0 Unported license:  http://creativecommons.org/licenses/by-sa/3.0/legalcode

With the Super Bowl airing today, and the Olympics starting on February 7 (next
Friday), there will soon be many highly fit individuals running, jumping, and
skiing their way across our television sets!  While I will certainly never be as
physically fit as an Olympic figure skater or skier, I would hope to achieve at
least an acceptable level for the average person. This brings up a
question...what exactly does it mean to be “physically fit”? 

By definition, physical fitness is, “a general state of health and well-being or specifically the ability to perform aspects of sports or occupations” (from the Wikipedia website on Physical Fitness).  So in general, to be physically fit means you should be able to perform your daily duties and actions without much difficulty and without getting too tired.  A person who has poor physical fitness will become tired from simple activities, such as climbing a staircase or walking from one room to another.  This can be due to several causes, such as poor diet, low physical activity, obesity (excess body fat), or a heart condition.  
 
What makes a fit person’s body so different from that of an unfit person?  First, if a person is in better physical condition they will tend to have less body fat than a person who is in poor physical condition, and so will have less weight to move around during physical activity.  A lighter body will put less stress on their bones and joints, too. In addition, there are some differences between the bodies of a person in good physical condition and a person in poor condition which may not be so obvious.  These include cardiovascular and muscular fitness.

When a person is in good cardiovascular condition (that is, their heart and lungs are in good condition), the volume of blood their heart is able to pump with each beat increases, and so does the amount of blood in their body.  This means that every time their heart beats, more blood is carried to their muscles, bringing oxygen and nutrients and carrying away waste more efficiently.  This means that their heart will have to beat more slowly when they are at rest, and that it will return to resting rate more quickly after exercise,
because they can supply their bodies with oxygen and nutrients (and get it to return to normal) with fewer beats per minute. 

Think of a person’s body as a city, and their cardiovascular system as the streets and highways carrying people around to all the organs and tissues.  If a person is in good cardiovascular condition, their city streets and highways are wider and well maintained, and so more cars can get where they need to go faster.  If they are in poor cardiovascular condition however, the streets and highways are
narrow, and can carry fewer cars at one time.

When a person’s muscles are in good condition, the muscles have more fibers and more blood vessels, and can therefore supply more power.  Think of the muscles as like ropes or cables that move our bodies: if the ropes are bigger and have more fibers (that is, more fibers that make up the rope), they will be able to
lift and pull larger amounts of weight.  The added blood vessels allow more oxygen and nutrients to flow to the muscles too, allowing them to work more efficiently (like the wider streets and highways in our last example).  

So how can we measure just how physically fit we are?  Through a series of tests measuring
your heart rate in number of beats per minute, we can get a good idea of just how fit you are.


TRY IT!


Here’s what you’ll need:


1.   A stopwatch or a watch with a sweep second hand

2.   A clean table you can lie down on or a clean towel to lie down on the floor

3.   Enough space to jog in place


Here’s what to do:


First, measure your standing heart rate.

1.   Stand upright for 2 minutes.  Be sure to stand still!

2.   With your index and middle finger, find the pulse at your wrist or your neck below your jaw bone.

3.   Count the number of times you feel your heart beat in 15 seconds.  Time this with your watch or stopwatch, and write down the number of beats.

4.   Multiply this number by 4 to get the number of beats per minute.

5.   Find the number of beats per minute in Table 1 below, and record how many points you earned.  Be sure to write this down!

 Next, measure your resting heart rate.

5.   Lie down on the table or the floor on a clean towel for 2 minutes.

6.   Record your heart rate as you did for your standing heart rate by repeating steps 2-4 above.

7.   Find the number of beats per minute in Table 2 below, and record how many points you earned.  Be sure to write this down!

Finally, measure your heart rate just after exercise, and how long it takes to return to normal.

8.   Jog in place for 10 seconds.  Time this with your watch or stopwatch.

9.   As soon as you stop, immediately begin recording how many times you feel your heart beat in 15 seconds.  Write this number down.

10.  Continue recording how many times your heart beats every 15 seconds until the number is the same as when you took your standing heart rate in step 3.  Write each number down.

11.  Count how many numbers you had to write down, and divide that number by 4.  This is how many minutes it took for your heart rate to return to the normal standing rate. 

12.  Multiply the first number you wrote down immediately after exercise by 4 to get beats per minute.  Be sure to write this down!

13.  Find the number of minutes it took for your heart rate to return to normal in Table 3 below, and record how many points you earned. Be sure to write this down!  If it took longer than 2 minutes, give
yourself 6 points.

14.  Subtract your standing heart rate from your heart rate just after exercise.  This is your heart rate
increase after exercise.

15.  Finally, in Table 4 below, find your standing heart rate on the left, and use the heart rate increase after exercise value on the top to find your points.  Write this down!

16.  Add up all the points you earned (steps 5, 7, 13, and 15).  Use the scale below to determine your level of fitness.

 
Are you as fit as you thought?  If you are not, why do you believe that is?  Do you need to get more exercise, or eat healthier?  
 
If you are not as fit as you want, try increasing your physical activity over the next few weeks, and repeat the test in one month.  See if you can improve your fitness level!



References for more information:


CDC: Physiological Responses and Long-Term Adaptations to Exercise
(http://www.cdc.gov/nccdphp/sgr/pdf/chap3.pdf)


Vernier Software and Technology website
(http://www2.vernier.com/sample_labs/BWV-27-COMP-heart_rate_physical_fitness.pdf)

Wikipedia: Physical Fitness (http://en.wikipedia.org/wiki/Physical_fitness)