Birth of a Plant From a Seed

Janet A. Elkins                Douglass Middle S & M Academy
                               534 N. Waller
                               Chicago IL 60644
                               (312) 534-6176

Objectives:

     Students shall be able to label parts of a dicotyledon seed by function 
as well as by proper names.

Materials needed:

     2 each lima beans, and red kidney beans 
     1 hand lens
     1 single edged razor OR scalpel
     colored paper, pencils, crayons, scissors, glue
     iodine, to test for starch (opt.)
     envelopes containing "job" vocabulary as well as the proper name, as 
follows:
     seed embryo, seed coat, food (cotyledons), root (radicle), stem and leaves 
     (plumule), hylum, microphyle, internal landmarks, internal structures

Strategy:

     Students will compare and contrast a dry bean versus a rehydrated bean, 
both lima and red kidney.  24 hours is needed to "fluff" the dried beans.  
Students can do this for themselves.  CAUTION: DO NOT soak for more than 24 
hours as the seed coats come off, and the likelihood of decomposition (rotting) 
is increased, with the growth of some quite interesting molds.

     The external landmarks of the microphyle and hylum are easier to see on 
the dried bean, although the rehydrated beans will show the interior structures 
better as they will be larger.

     Part 1:  Students are to examine both dried beans, and locate the 
"bellybutton", hylum, of each, then scan carefully for the "dimple", microphyle. 
Drawing what has been described and observed can take place here, depending on 
time limitations and supplies.

     Part 2:  Have the students take all the vocabulary words out of the 
envelope, and separate them into columns of WORDS KNOWN and WORDS UNKNOWN.  
Further separate the KNOWNS into the EXTERNAL LANDMARKS and INTERNAL STRUCTURES.
Place the known names on the drawing.  Have students attempt pronunciation of 
new words.  Offer crutches, such as plumule is for the stem and leaves, like a 
plume.  This is also a good time to look at some of the roots, like micro-, 
meaning little.  New words need to be mounted on the individual student 
drawings.  Having the function name and the proper name paired will give a good 
study guide, incorporating the new and old knowledge.

Performance Assessment:

     Words will be correctly paired on student drawings.