1999-00 -- 05-06 Academic Years
14 September 1999: Chuck Buzek (Spry School)
took us out to the IIT meadow and led a discussion on the feasibility of science fair experiments involving biology. Digging down through soil might reveal different organisms at different depths. Trees may tend to grow more in one direction than another. How could we find out? Chuck gave us some ways to learn how. Great!
12 October 1999: John Scavo [Richards Voc HS]
26 October 1999: Glenda Ellis (Williams School)
handed out rulers (metric), a Data & Observations page, and we each got several maple leaves. She had us measure and record (in cm) from the tip of each leaf to the bottom of its stem (Length, and then by having us raise our hands, she determined how many leaves had lengths of 7.0 cm, 7.5 cm, etc. up to about 13.0 cm. Using this data, a graph of the number of leaves (vertical axis) of a given length (horizontal axis) could be plotted, showing variation in leaf length. What an interesting idea! ...and such a good way to get students involved in observation, measurement, graphing, and possible interpretations!
02 May 2000: Chuck Buzek (Spry School)
took us outside to "measure" tree heights and canopy widths (related in most cases). The nice weather made this a pleasant thing do, and we gained some insight into the characteristics of trees and how they may be measured. A fine way to end our last meeting for this semester!
09 October 2001:
Barbara Pawela (May School, retired)
Barbara showed some plants just taken from her yard [or "garden", if you speak British], as well as those obtained elsewhere We investigated the structure, life cycle, and process of reproduction for the following plants:
To complement the discussion of the specimens, Barbara distributed a handout, What Do Root Hairs Look Like?
Barbara also handed out bean seeds to be grown in the zip-lock bags. The marigold and pumpkin seeds should be placed in potting soil to make the plants. We will wait and watch for them to grow!
23 October 2001:
Carolyn McGee and Carolyn McBride (Manierre School)
were the dynamic duo who used a variety of different-sized pumpkins to illustrate nutrition facts about pumpkins and other fruits and vegetables. They passed out activity sheets that guided investigation of different pumpkins. We were given plastic gloves, and we cut the pumpkins in order to see how many seeds there were, and what kinds, in different pumpkins. There are hundreds of websites concerning pumpkins; for example, see http://www.urbanext.uiuc.edu/pumpkins/nutrition.html and http://www.pumpkinnook.com/facts/nutrition.htm.
In cutting the pumpkins open and counting the seeds, we notice that the seeds are arranged inside the pumpkin in an organized manner, which probably reflects the structure of the ovary of the female flowers. Here are the numbers for pumpkin seeds:
|Tiny Pumpkin||100 seeds|
|Medium Pumpkin||350 seeds|
|Medium Pumpkin||405 seeds|
|Large Pumpkin||510 seeds|
19 February 2002:
Fred Schaal (Lane HS Math -- Visitor)
Fred explained that he often picks up fallen branches that happen to have buds on them, brings them home, puts them with water in a vase, and waits for the bulbs to open within a few days. He has had trouble in making this work the last few times, and asked whether anybody knew of a "trick substance" to add to the water to improve the likelihood of success. Any suggestions? We then had an extensive discussion as to the best way to get an Amaryllis Bulb to sprout inside the house in winter. Good, Fred!
Note added by PJ: The following information is an excerpt from the website The Joys of an Herb Garden: http://www.orchardsedge.com/articles/herb-and-flower-gardening/herb?referer=tools%2Fbahco
... "In winter, indoor space is used to start new seedlings or cuttings to be placed outside in the spring, using natural sunlight to ripen the plants. This routine will provide at least 3 outdoor/greenhouse harvests per year. If more space is available to constantly be starting indoors and flowering 2nd harvest plants outdoors, harvests are possible every 60 days in many areas, with a small indoor harvest in the winter as a possibility as well.
The basic strategy of year round production is to understand the plant has two growth cycles. At germination the plant enters into a vegetative state and will be able to use all the continuous light you can give it. This means there is no dark cycle required. The plant will [... photosynthesize ...] constantly and grow faster than it would outdoors with long evenings. Photosynthesis stops during dark periods and the plant uses sugars produced to build during the evening. This is not a requirement and the plant will grow faster at this stage with continuous photosynthesis (constant light)." ...
That website contains quite detailed information of relevance. For sprouting Amaryllis Africanus bulbs, check out WINTERTIME BULB TALK: http://www.dutchbulbs.com/bulbs/ or Forcing Bulbs for Early Winter Cheer: http://www.johannsens.com/newsletters/page3fall97.html.
23 April 2002:
Barbara Pawela (retired and happily active) -- Spring Planting
Barbara showed her tomato plants that sprouted from seeds 2½ weeks ago -- which are 2 -3 cm tall -- most with just 2 leaves, which are called cotyledons. For further information on nurturing and growing tomato plants, see the Tomatosphere Tips website: http://www.tomatosphere.org.
Barb then put two clear plastic cups [about 250 ml] on the table. One of them was filled with potting soil, and the other was filled with "Schultz Seed Starter", which contains vermiculite [soil conditioner] and other materials. For more details concerning this material, see the Schultz Company website http://www.schultz.com/.
We examined each cup for porosity of material, and added the same fixed volume of water to each one. The potting soil was able to absorb water more readily. The seed starter will keep things a little more dry around germinating seeds, and helps prevent rotting of new seedlings, a problem that is very common in an overly moist environment.
Barb then had us start bean seedlings by placing the beans onto dampened paper towels, which we then sealed in zip-lock bags. We next planted cantaloupe and watermelon seedlings in pots. Now we are ready for Spring to come, thanks to Barbara!
08 October 2002:
Teri Roland [Joliet West HS] Why
Leaves Change Color [
Teri first asked us for an explanation, and after rejecting several suggestions --- such as that the trees were blushing because they were losing their "clothes" --- she explained that the fall colors result from chemical compounds that have been in the leaves all summer, but have been "drowned out" by a much higher concentration of green chlorophyll. When winter approaches, it is a signal (not fully understood but probably triggered by fewer hours of sunlight) to the (deciduous) tree to shut down chlorophyll production and prepare for its winter "nap". Teri started by putting spinach leaves in a blender, adding some acetone (nail polish remover) and "pureeing" to get a dark green solution. We then put a small drop on a long strip of chromatography paper (other paper can also be used, e.g. coffee filters, regular filter paper, certain paper towels, ... ) and inserted it into test tubes containing a solvent (90% petroleum ether and 10 % acetone) which Teri had developed by experimenting with different mixtures. In a short time the colored pigments started moving up the paper (by capillary action) and we clearly saw a separation of colors with green moving faster and yellow following up behind. The separation occurs because the molecules making up the various pigments have different attractions for the paper; the ones more strongly attracted moving more slowly. By comparing the behavior of a sample with known compounds, it is possible to rule out certain compounds because of different rates of movement. Teri also showed us a faster way to prepare the chromatographic strips, which would be especially useful for comparing leaves from several different trees . The leaf is placed on the paper, and the edge of a coin is pressed against the outer surface firmly enough to make a "grass stain" on the paper. Then proceed as before. What a good fall project with a lot science in it for further investigation! [Many plants will show more than one green pigment, indicating that there are different types of chlorophyll present.]
22 October 2002: Christine Scott [Beethoven Elementary
School] and Lilla Green [Hartigan Elementary School,
A Twig's Story
Christine and Lilla distributed the handout, showed and discussed twigs, and passed out twigs for examination. We studied the twigs to identify scars from which leaves grow in the spring. The number of terminal bud scars shows the age of the branch, in years. Terminal buds are located where new growth will occur, and lateral buds for sideways growth. This growth can yield new branches or new roots, depending on the environment of the bud. Features of twigs, such as the shape of the leaf scars and the number of terminal buds at the tip of the twig (for twigs that come from the end of a branch) can be used to identify the species from which the twig came.
The twig article is found in the book The budding botanist: investigations with plants, AIMS activities. [http://www.aimsedu.org AIMS Education Foundation 1993] ISBN 1-881431-40-1:
Abstract: "Activities Integrating Mathematics and Science (AIMS) books primarily integrate mathematics and science but also provide coordinating activities related to other curriculum areas including language arts, social studies, physical education, art, and music from grades K to 9. This activity book is designed for students in grades 3 to 6. The book's objective is to foster students' interest in plants by teaching introductory knowledge of seed plants, their structures, and their economic importance. Particular attention is given to seeds (their structure, how they grow, their properties, and how they are dispersed); plants (their structure, how plant parts work, photosynthesis, and development of seed and fruit); and a short look at the structure of the plant cells. The activities generally include an introductory statement, math skills, science processes, materials, key questions, classroom management suggestions, procedures, discussion questions, extensions, curriculum correlations with other disciplines, and illustrated student worksheets. The book includes a table of contents, a glossary, and a list of the intended mathematics and science process skills."Great Lesson, Christine and Lilla!
Contents: Conceptual overview; Letter to parents; Why are plants important?; Enviroscape; Seed facts; Seed search; Dissect a seed; Seed scavenger hunt; Germination study; Test a seed; Exploring germination; Comparing germination; Seed plants; Cones and needles; History of a tree; Observe a tree; A flower study; Seeds from fruits; Plant structure facts; Down under; Herb and woody; A twig's story; Leaf facts; Leaves; Leaf printing; Photosynthesis; Transpiration; Cactus; New plant discovery; Cell facts; Model of a cell; Focus on cells; Cell your fruits and vegetables; Glossary; Literature list. Source: http://store.aimsedu.org/aims_store/books/the-budding-botanist.html.
22 October 2002:
Chris Etapa [Gunsaulus Academy] Observations
Chris showed three jars of sunflower seeds and described a class activity of "observations". The idea was to describe the different, individual sunflower seeds as objects. One might use such phrases as oval shaped, black and white, color, pattern, size, shape, texture, and number and arrangement of stripes. We decided that "stripes" provided the best method of categorization of our seeds. One could use the descriptions given in one class to see if another class could pick out the individual seeds from the description. Results are often inconclusive because descriptions are not sufficiently different. Such an activity is a convenient way, at the beginning of the school year, to hone observational skills and focus on the need for precision and attention to detail in recording data of all kinds. Good idea, Chris.
11 February 2003:
Fred Schaal [Lane Tech HS, Physics] Tree
Fred described measuring the circumference c (in inches) of a tree (with roughly circular cross section) in order to determine its diameter d (in inches), by dividing by p » 22/7 (or, better yet, p » 355/113):
25 March 2003:
Ana Timbers [Haven Middle School,
Starch in Green Leaves
Ana had a beautiful, large, hand-lettered and hand-drawn poster, which she posted on the blackboard in the front of the class, to help us follow these instructions:
Why does the iodine produce the color change in the leaf? [Actually, it was too difficult to see any color change because the iodine solution too concentrated and would cause a dark stain, even with out starch present.. Therese suggested diluting the iodine solution with isopropyl alcohol. Then the iodine had a golden color --- easily distinguishable by that black color made in the presence of starch.] We concluded that the iodine had reacted with the starch in the leaf, which remained there even though the chlorophyll had been removed previously. To demonstrate the starch reaction more vividly, Marva Anyanwu suggested we put iodine on a piece of bread --- and that turned out to produce a very striking color change.
We experienced the Biology of everyday life! Thanks, Ana!
25 March 2003:
Brenda Daniel [Fuller Elementary School] and Erma Lee [Williams
School] Different Salads in a Bowl
Erma and Brenda made a salad consisting of various mystery ingredients, which we identified and categorized according to the organism, and part of organism, that was the source of each:
|Crackers||Flour, Oil (from seeds)|
|Mayonnaise||Eggs (from animals), oil (from seeds)|
|Shrimp, chicken||Animal muscle|
|Drinks||High fructose corn syrup
(from corn kernels; i.e., seeds)
08 April 2003:
Brenda Daniel [Fuller Elementary School] and Erma Lee [Williams
School] Edible Plant Parts
Erma and Brenda followed up their presentation at the previous meeting by handing out this List of edible plants (roots, seeds, fruits, leaves, and pods):
|carrots||peas||artichokes||avocados||Brussel sprouts||green beans|
|Jerusalem artichokes||pumpkin seeds||bananas||bell peppers||beet greens||okra|
|leeks||sunflower seeds||berries||cranberries||cabbages||sugar snap-snow peas|
A deliciously interesting lesson, Brenda and Erma!
22 April 2003:
Jyotiben Desai [Du Sable HS]
Mining for Peanuts [handout]
J Desai helped us celebrate Earth Day [22 April 2003 -- TODAY!] with her activity. Each group put several glass marbles into a TV dinner tray, and then covered them with potting soil, raking the potting soil over the marbles so that they could not be seen. Each group also made a map of the locations of their marbles. We then exchanged trays, and mined for marbles! for about 5 minutes. We used small objects, such as paper clips, Popsicle® sticks, and coffee stirrers. as probes. Finally the trays were returned to the original group that planted them, who assessed now much damage was done to the soil surface by this mining operation. It is a reminder that activities that provide benefit to society, such as digging marbles, can have undesirable, and often unanticipated, side effects. Putting layers of soil, then sand, then soil over the marbles would be a more complicated, but perhaps better, model of mining, since the disturbance of the soil by our mining operations would have been much more visible and much more difficult to restore. Use of peanuts instead of marbles is another suggestion. The peanuts, when found, could be shelled, and the shells collected as a model of the waste (tailings, slag, polluted water, particulates) produced from mining operations.
A very good lesson on conservation. This lesson appears in the following book, (p 222):
Holt Environmental Science [1996: ISBN 0-03-003133-8]
Holt, Rinehart and Winston, Inc
1120 South Capital of Texas Highway
Austin, Texas 78746
Comment by PJ: The peanut plant, like the soybean, is a legume, which enriches the soil though nitrogen fixation. Farmers typically plant in rows, use a type of turning plow to turn over the edible subterranean nodules [often called goober peas in the 19th century, and referred to as peanuts today]. Some time later the rest of the plant is plowed into the ground to encourage aeration of the soil and composting of organic material. Legumes actually enrich the soil when cultivated in this way --- in contrast to potato farming, which removes vast amounts of nutrients with each crop.
Great job. Thanks, J!
22 April 2003:
Marva Anyanwu [Wendell Green School]
Potatoes on the Desk
Marva placed three potatoes on the desk, and asked what students would say [or think!] if they saw them on the teacher/s desk when they first came into the classroom. Various ideas were suggested. She then stated that we would use them to describe and visualize the process known as cloning. When we cut out a little piece of potato containing an "eye", we might expect to be able to grow a potato exactly like the old one, since the DNA should be identical to the original potato. However, we actually would produce a new plant, with an identifiably different potato (tubers). How could that be? Ben Stark [IIT] then led a discussion of cloning, including a more extended description of cloning in plants, cloning in animals, and the famous cloned sheep, Dolly! For additional information on cloning, see, for example Beyond Jurassic Park: Real Science with Ancient DNA http://www.plantmanagementnetwork.org/pub/php/review/ancientdna/: and the Scientific American News Scan feature: Ma's Eyes; Not her ways [April 2003] http://www.sciam.com/article.cfm?colID=5&articleID=000DE213-6B0F-1E61-A98A809EC5880105.
Very nice, Marva!
07 October 2003:
Chris Etapa [Gunsaulas
Academy] Nature Walk, Part I
Chris took us outdoors on a stroll through the campus to collect several specimens of various types of leaves. We obtained simple leaves, compound leaves, single leaves, and leaf bunches still on their branches. We will take these home, put them between layers of newspaper under weight, and press them. At the next class we will bring back the pressed leaves, to continue with Part II of this experiment.
What happens next time?? Very nice, Chris!
21 October 2003:
Chris Etapa [Gunsaulas
Academy] Nature Walk, Part II
We finished the class with a follow-up to the previous lesson [bc100703.html], where we brought in a wide variety of autumn leaves. Chris reviewed some of the physical features of leaves used to identify them. Then she showed us some (fantastic) collages made by students in her science club using leaves they had brought to class, and she gave us 15 minutes to make a collage with our leaves. The collages used leaves of various shapes and sizes to make exceptionally creative images of animals: fish, an elephant, birds, etc. We were expected to identify as many tree species as possible, and to describe the type of leaves shown in our drawing. Glue was used to attach the flattened leaves to a heavy paper backing.
21 October 2003:
Earl Zwicker called attention to an article by David
Perlman in The San Francisco Chronicle:
BIZARRE BURROWING PURPLE FROG FOUND: Mysterious creature hails
from time of Gondwanaland
"...In the verdant countryside of western India along the Arabian Sea, villagers digging a well in a cardamom plantation five years ago were astonished to spot a squat, bulbous purple frog sitting immobile nearly seven feet down in the mud. ... With a pointed snout, glistening deep purple skin, red eyes and a powerful talent for burrowing into the ground, it looked like something primitive. Indeed it was. The family appears to date back more than 200 million years to a time when Africa and India were joined in a single vast supercontinent now called Gondwanaland. By 150 million years ago that continent had broken up into chunks of land masses that included Madagascar, the Seychelles, and the western Ghats of India.. ... " For more details see the following website: http://snurl.com/2pgt
04 November 2003:
School] Leaf Art
Wanda provided follow-up to last week's "Leaf Art" activity by showing us pictures made by her students and asking us what they represented. In some cases there was a consensus, in others we came up with several different possibilities, and in a few cases they were relegated to "modern art". Thanks, Wanda.
04 May 2004:
Christine Scott [Beethoven Elementary
Christine brought in various plant parts containing seeds: squash, orange, apple, peanut, as well as assorted dried beans. She gave each of us a baggy containing various types of seeds, as well as a key made up as a grid. We tried to match each of our seeds with the entries on the grid. Christine then passed around a template, in which the seeds were taped onto the appropriate location on the grid. Magnifying glasses were very helpful in identifying the smaller seeds. This was a fascinating phenomenological exercise, and we found it challenging to make an identification of a particular seed. One possible extension might be to obtain 10 seeds of the same type, weigh each of them and note the range in masses, and discuss why individual seeds vary considerably in size, strength of integument, etc.
Thanks for the ideas, Chris!
12 April 2005:
Chris Etapa [Gunsaulas
Academy] Greenhouses on
This is another activity that is part of the greenhouse project that Chris had talked about earlier in the year. Chris brought potting soil, which we moistened and which we used to fill 1 quart Ziploc™ bags. The soil was packed into the corners (to help the bag stand up) up to near the top of the bag (but leaving enough room for the bag to close). We sprinkled about 5- 6 seeds (we used pickling cucumbers) on top and sealed the bag. Put in a sunny window and let the seeds sprout until they are pushing against the top of the bag. Then open the bags and let the plants grow further until they can be transplanted. Each child's name and other information can be easily recorded on the bag. This activity is appropriate for many grade levels, with experiments (vary light, temperature, etc.) added and discussions made more sophisticated as the grade level increases.
This was a blast! Very good, Chris!
26 April 2005:
Ben Stark [IIT Biology]
Seeds of Wisdom
Ben brought in his "seed sprouter" from the last session -- for details see Chris Etapa's presentation from the last SMILE meeting bc041205.html. It had been very successful, with all planted seeds apparently sprouting. There were six healthy shoots, some nearly 20 cm long with first leaves. The zip-lock bag had been open for about 10 days to permit the shoots space to grow, but the soil was still fairly moist below the surface -- although water had been added a few hours before.