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:

• Poke Salad [as in the 60s  Tony Joe White http://www.tonyjoewhite.com song Polk Salad Annie http://www.kulichki.com/dassin/lyrics/polk_salad_annie.html].  A quintessential element of soul food. You can eat the leaves only when they are young and tender, and you should pass on the poisonous purple berries!  One explanation for the name is that you carry it home in a poke (sack) from where the pokeweed [Phytolacca americana: click here to see a picture] grows on uncultivated land at the edge of  the woods.  For other opinions and more information see the websites http://waynesword.palomar.edu/ecoph24.htm and especially http://www.durangotexas.com/dustytrails/texasfood.htm.
• Marigolds
• Parsley Sprouts
• Oranges
• Tomato Plants --- including the roots, for examination of root hairs [see below].
• Sprouted Sweet Potatoes [see http://familyfun.go.com/arts-and-crafts/season/feature/famf49jungle/famf49jungle5.html --- only un-sprouted ones should be used in sweet potato pie: http://members.tripod.com/~Nancy_J/kwanzaa.htm]

To complement the discussion of the specimens, Barbara distributed a handout, What Do Root Hairs Look Like?

• Materials:
  paper towel, zip-lock bags, stapler, push pins, hand lens, seeds, water
• Procedure:
  1. Moisten a paper towel, fold it, and place it in a plastic bag.
  2. Lay the bag on a flat surface and put the seeds on the towel.
  3. Staple three edges of the towel to the bag. Seal the top of the bag and hang it, adding small amounts of water to keep the seeds from drying out.
  4. Check the seeds each day. When the roots are about 4 cm long, remove the seeds and examine the roots with a hand lens. Draw what you see.
• What did you learn?
  How can you use what you learned?
  1. Q: What do root hairs look like?
     A: Root hairs are very fine hairs sticking out of the root.
  2. Q: Why do plants have root hairs?
     A: Root hairs help the plant absorb water from the soil surrounding the plant.
  3. Q: Do plants that live in water need root hairs? Explain.
     A: No. Plants that grow in water do not need root hairs because they can absorb enough water directly through their roots.

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!

Marva Anyanwu (Lincoln Park HS) The Tensile Strength of Spaghetti (handout)
The handout explained that "raw spaghetti" is a surprisingly strong material --- before you cook it.  Spaghetti***  is categorized by thickness of the strands.  In particular, angel hair spaghetti is thin, and "regular spaghetti" is described as #8 on the boxes.

Tensile strength  is measured by stretching an object until it breaks.  A rope used in a tug-of-war is under tension.  Compression occurs when forces push into an object. For example, a pillar supporting a building is subject to compression.  When a long, thin object is supported horizontally at its ends and pushed down at the middle, the top edge is under compression and the bottom edge is under tension.

We worked in groups, using both "thick" and "thin" spaghetti. We placed a spaghetti strand with  the ends on two desks, and over the strand we looped a piece of string that was tied to a Styrofoam™ cup.  We added weights to the cup until the spaghetti strand broke, and recorded the data.  We drew the following conclusions:

• Variations in the technique for adding weights could produce variable results.  For example, the results were different when we dropped weights into the cups, as opposed to placing them inside more gently.  Spaghetti of the same size from different manufacturers could also yield different results
  .
• Three of the four groups found that a thin (angel hair) spaghetti strand was stronger than a regular (#8) strand.
  
• We tested the hypothesis as to whether two pieces of spaghetti would hold twice as much weight as one piece, and found that it was false! There may have been problems in alignment of the pieces of spaghetti, so that they would share the load equally.

*** The word spaghetti means little strings in Italian and is always plural. The rumor that spaghetti plants grow in long thin patches between lanes on interstate highways is false. After all, spaghetti requires a hot, dark environment for proper development.

Notes taken by Ben Stark