Today in science class we dissected a worm. And it was really fun.
Now, this is not my first dissection ever....
When we first got Jackie we thought that she was a he and his name was Jack. When Jack laid an egg, however, we knew we had made a mistake. So we re-named our pet Jackie and lived a happy enough life with us. Until the fateful day when an egg she was trying to lay, got stuck, and she died.
Then, because Mom and I are curious homeschoolers, we dissected Jackie and saw her brain. It was all very interesting.
Anyway, today's dissection of an earth worm was very, very different from dissecting one's Parakeet. For one, I actually knew what I was doing - I wasn't just watching Mom hack away at the bird, trying to get it open. Two, I knew what I was looking for. In our lab books we had to draw a picture of what we saw and label all the internal structures we saw.
Did you know that worms acutally have a head and a tail? The head is closest to the clitellum, which is the discolored rise in the worm (the clitellum aids in reproduction).
Also, worms don't eat dirt. They take in dirt and then eat the tiny particles of leaves and stuff that they find in the dirt.
We started the dissection by gathering supplies. (Disection kit... the worm... the thing you put the worm on.... The gloves are really for the mad scientist look since I didn't actually end up using them.)
Then we had to feel the worm's anterior and posterior sides for setae (aka, we had to feel the front and back ends for little hairs which aid in locomotion).
Next step: Pin the worm to the blue tub thing and cut it open (sorry the picture is sideways... Don't know how to fix it).
The segments of the worm continue on the inside.
My friend accidentally opened the wrong end... But I'm glad she did! Because you can see the dirt that is about to be pooped out.
The front end of the worm (with all the organs) looks like this:
How interesting, right? Starting at the left of the picture... At the very front, is the pharynx which then leads to the aortic arches (the little black things). Then there's some seminal vesicles which store the sperm, and some seminal receptacles which contains eggs. Then there's a crop and gizzard, which help in the food-eating process. And then the looooooooooooooooooonng intestine which stretches to the back of the worm. The little black line on the intestine is the dorsal nerve chord. There's another nerve chord underneath the intestine.
It is so interesting to learn about something and study the pictures, and then see the actual thing with your own eyes!
Live long and prosper.