Field of Science

Showing posts with label peanuts. Show all posts
Showing posts with label peanuts. Show all posts

Bean seed redux

You try your best, you really do, but it never seems to be  enough.  This is the single most commonly encountered error that TPP sees.  He has certainly corrected it in enough biology textbooks (always accurately identifies botanically ignorant authorship), and quite recently posted a lesson on bean seeds. Of course, no one should actually read the Huffington Post for their science reporting, and although memory fails TPP on the specifics, he's certain he has corrected Landess Kearns (the author) before.  So here it is once again, sorry, Landess you are incorrect in your identification of a peanut "embryo".
 The "little" nub at the right is identified as the peanut embryo.  WRONG!  What do you think those two big things are?  This peanut plant at the embryonic  stage consists of a pair of cotyledons that function in food storage, and they are attached the main axis of the embryo.  The pointy end to the right is the embryonic root axis and above the attachment point (node) of the cotyledons is at least one pair of heart-shaped true leaves (each neatly folded in half).  The whole DANG thing is the embryo; this illustration shows 
2 peanuts, 2 embryos.  At maturity there is no endosperm in this seed, just a seed coat (removed in this case) and the embryo.  The endosperm was absorbed by the embryo as it grew.  But so many textbooks say seeds have endosperm that this misconception continues, perhaps because people cannot grasp that at this embryonic stage two leaves are so much bigger than the rest of the plant. So Landess, here's a helpful hint: split peas aren't split!  But they still make good cotyledon soup. And please don't try to figure out "pine nuts" on your own.

Beans versus nuts

Today's laboratory focuses on beans, legumes.  It's a fun lab with lots of cooking and disecting and eating.  Peanuts, the very name, cause a bit of confusion because they are not a nut at all but a pea in a pod, a dry indehiscent (does split open by itself) pod that grows under ground.  Of course this mornings news was all about nuts of the political persuasion.  Nuts who are obsessed with causing Obama to fail at any cost; nuts who will do any amount of damage to the USA to accomplish this goal.  In making this observation, it occurs to TPP that we might even say "pea-brained nuts" because none of this is very smart.  Indeed, the fear that Obama-care might work has spawned a disinformation campaign of epic proportions.  This however does demonstrate that ideology is no way to govern, and the GnOPe (the G is silent you recall) party continues to pursue their agenda because it's the will of the people, all 22%.  Wonder how many of my students even know what happened?