Here's a pretty neat lesson exploring mold - courtesy of elementary science teachers in Orange County Public Schools.
KEY QUESTION
What can we grow without water, warmth or sunlight?
BACKGROUND INFORMATION
Mold is a form of fungus that grows and reproduces very quickly. Mold produces tiny cells with hard coverings called spores. Spores float through the air and land on all kinds of things, including food. That is why bread already has spores on it when placed in a bag.
Molds have both good and bad uses. Some molds make foods taste and smell bad. However, many cheeses depend upon mold for their good taste. The green mold that forms on bread and oranges is used to make penicillin, an important antibiotic.
MATERIALS
small pieces of food such as bread without preservatives,
cheddar cheese, overripe vegetables or fruit
hand lens
resealable plastic bags
paper towels
water
soil or dust
tape and/or marker for labeling bags
TEACHING TIPS
Before beginning this experiment, make sure no students have allergy problems associated with molds. Be sure everyone washes their hands after touching the bags. When experiment is completed, throw the bags away unopened.
A FEW QUESTIONS TO ASK.
What is mold? Have you ever seen mold? Where did you see it? In what type of environment was the mold growing? In what kinds of environments can we test the growth of mold? (e.g., light, dark, moist, dry, etc.)
EXPLORE
1. Have each group collect pieces from a central distribution area. (Or prepare a paper plate with the food pieces for each group ahead of time. One member of the group can pick up the plate.) Have students inflate their seven plastic bags to make sure there are no holes in them. Groups should label each of their 4 bags with group names, the word CONTROL, and one type of food. The other 3 bags should each be labeled with their group name, the word VARIABLE, and the variable being tested.
2. Have students place each kind of food in a different bag. Make sure each group has at least four bags with bits of bread. One bag will be stored in a dark place and serve as a control. The other bags of bread will be used to explore variables of light, temperature, and moisture. Record results in student science notebooks.
3. Have students put a pinch of soil or dust in each bag. This provides spores for the production of molds. There should also be a dampened (not soaking wet) paper towel in each bag.
4. Have students leave a little bit of air in each bag so they don’t lay entirely flat, then zip bags closed.
5. Encourage students to be creative when thinking of places to store the VARIABLE bags of bread. Place one in a refrigerator or another cool place to see if temperature affects mold growth. Place one bag in a place that is sun. Add little or no water to the third variable bag to see if moisture affects mold growth.
6. After several days, mold should appear. Remind students: DO NOT OPEN BAGS. After using hand lenses to examine the mold through the bags, throw unopened bags away. WASH HANDS AFTER HANDLING!
NOW ASK STUDENTS THESE QUESTIONS.
How many different colors of molds do you see?
Do different colors and kinds of molds grow on different foods?
How many types of mold are in each bag?
Did all bags in the control group produce mold?
Did all bags in variable group produce mold?
How do the control bags compare with the bags in the variable groups?
What type of environment is best for growing mold?
RECORDING OBSERVATIONS
Have students record observations and draw each type of mold. Emphasize how important it is to make drawings as accurate as possible, in case someone else looks at them for information.
Invite opinions as to whether students think the mold they grew is harmful or helpful.
TAKING THE NEXT STEP.
Let students set up another investigation of molds. Have them pour some tomato soup into 3 clean baby food jars. In jar 1, have students sprinkle some breadcrumbs. In jar 2, let a student dip his or her finger into the soup. A small amount of dirt should be put into jar 3. Have students seal all containers with plastic wrap and tape securely. Jars should be placed in a warm dark area. Have students record observations after a week. Remind students NOT TO OPEN THE JARS!
ASSESSMENT
Have students research mold and list those that are beneficial and/or harmful to humans.
Summer Science Ideas
Those of us in Florida never quite get enough of the beach. As I am beginning to put together summer packets for my students I wanted to share some interesting science activities that families might consider for a beach vacation. Many of you might also be looking at an end of the year "beach party" and may find these activities helpful.
“Sand Castles” –
Using three different textures of sand, try to build the tallest sand castle. Limit construction to twenty minutes. At the conclusion of the activity what did you observe? What effect did the texture of the sand have on construction? Add water to the sand and repeat the activity. What role does water play in making the different sand samples more or less dense and pliable?
“Collecting Sand” –
Collect three different types of sand or soil. Observe what makes each the same or different. Weigh equal portions of each and compare the results. Observe the samples using a magnifier and describe what you observe.
“Making Sand” –
Collect materials which might be used to make sand. Include crushed shells and rocks. Place all of the materials in a large cloth sack and pound them with a hammer. Take the contents out and compare with various samples of sand.
“Sifting Sands” –
Construct 2’ by 2’ wire frames using wire of different weaves (from hardware cloth to screen). Use the frames as sieves and sift various sands. Is there a relationship between the sieve and the different sands? Will some sands not sift, while others pass through easily? The sieves can also be used for sorting small ocean animal skeletons, shells or other materials.
“What’s in the Water?” –Collect samples of water from various sources (bottle, pond, lake, rivers, puddles, ocean) and observe each through a microscope. How are the samples similar or different? Reflect upon the impact of pollutants.
“Sand Castles” –
Using three different textures of sand, try to build the tallest sand castle. Limit construction to twenty minutes. At the conclusion of the activity what did you observe? What effect did the texture of the sand have on construction? Add water to the sand and repeat the activity. What role does water play in making the different sand samples more or less dense and pliable?
“Collecting Sand” –
Collect three different types of sand or soil. Observe what makes each the same or different. Weigh equal portions of each and compare the results. Observe the samples using a magnifier and describe what you observe.
“Making Sand” –
Collect materials which might be used to make sand. Include crushed shells and rocks. Place all of the materials in a large cloth sack and pound them with a hammer. Take the contents out and compare with various samples of sand.
“Sifting Sands” –
Construct 2’ by 2’ wire frames using wire of different weaves (from hardware cloth to screen). Use the frames as sieves and sift various sands. Is there a relationship between the sieve and the different sands? Will some sands not sift, while others pass through easily? The sieves can also be used for sorting small ocean animal skeletons, shells or other materials.
“What’s in the Water?” –Collect samples of water from various sources (bottle, pond, lake, rivers, puddles, ocean) and observe each through a microscope. How are the samples similar or different? Reflect upon the impact of pollutants.
The Great American Paper Airplane Challenge
Here is a neat rainy day activity!
Your Challenge:
Use a piece of paper to construct an airplane capable of traveling at least five meters and landing at a designated target.
Materials which may be used:
One sheet of 8” X 11” copy paper
8” X 11” wax paper
8” X 11” cellophane wrap
no more than 12 inches of scotch tape
scissors
Your Challenge:
Use a piece of paper to construct an airplane capable of traveling at least five meters and landing at a designated target.
Materials which may be used:
One sheet of 8” X 11” copy paper
8” X 11” wax paper
8” X 11” cellophane wrap
no more than 12 inches of scotch tape
scissors
Paper Houses
Here’ a fun problem solving activity based upon a well known fairy tale. Everyone knows the story of the Three Little Pigs. But very few people are aware of the fourth pig. He was so lazy that he didn’t use hay, or stick, or bricks to build a house – he used paper!
Challenge students to construct a structure for the fourth little pig using only a piece of copy paper and a pair of scissors. Your “wolf” will try to knock down the house by placing a heavy object (like a wooden block or book) upon the roof of the house trying to make it collapse.
Allow the students time to plan, test and construct the houses. Finally test the strength of each house and observe the results. Repeat the activity each day for a week, allowing students the opportunity to modify and improve the designs. Consider adding more weight each day as an additional challenge. At the end of the week you will have learned about problem solving, discovered the power of innovation and come to better appreciate a wonderful fairy tale.
Challenge students to construct a structure for the fourth little pig using only a piece of copy paper and a pair of scissors. Your “wolf” will try to knock down the house by placing a heavy object (like a wooden block or book) upon the roof of the house trying to make it collapse.
Allow the students time to plan, test and construct the houses. Finally test the strength of each house and observe the results. Repeat the activity each day for a week, allowing students the opportunity to modify and improve the designs. Consider adding more weight each day as an additional challenge. At the end of the week you will have learned about problem solving, discovered the power of innovation and come to better appreciate a wonderful fairy tale.
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