Yesterday I had a Developmental Biology prac. We played around with chick embryos. It’s so hard. I can open the egg fine, take out some egg white, remove membranes and all that (I can even handle needles. Woah, that’s a big step). But I can’t inject ink underneath the embryo. My 2-day embryo (I called her Jil) got pushed to the edge and had bubbles everywhere so I couldn’t see the somites. I was waiting for a microscope (there wasn’t enough for everyone) and then someone knocked the egg over. It was actually funny because it gave me a chance to cry “Jil, noooo!!!!”
The 3-day egg (which I named Graeme) was easy to do because we didn’t need to inject dye. A lot of people hit blood vessels when they were trying to remove the membrane (which means the embryo dies). I didn’t hit a blood vessel. But when I was trying to remove the foot bud (the whole point of the prac), I heard a demonstrator tell my friend that hers was dead. So I took a closer look at Graeme and…his heart wasn’t beating! Nooooo! I think he got dehydrated. And that means that I can’t check on my embryo next week and see if I have good sterile techniques.
My Developmental Biology class is turning out to be pretty interesting. It looks like a class that has a tough exam but at least I’m learning interesting stuff (for now at least). Looking at all this embryo stuff, it’s gotten me thinking about the whole pregnancy termination and stem cell research issues. When does life begin? Some people think it’s when the mother gives birth; others think it’s when the egg gets fertilised.
Well, now that I know more about development, I think the begging of life could be the point when the cells become determined.
During the early stages, you can split cells apart and all the cells will develop into normal organisms. That’s what happens with identical twins, they originate from the single embryo. So, if you say that the moment of fertilisation is the point where life begins then does that mean that identical twins are a single life? I don’t think so. It suggests to me that it’s a stage before life begins, a precursor to life. It has the potential for life, just like eggs and spermies, but it itself is not life.
During embryonic development you can take cells from one place, put it in another and the embryo will develop normally (so, take potentially muscle cells, put them in the neural region and those cells will become neural cells). You can even put in cells from another species and it’s all good. That can’t be life.
Eventually, you get to the point where the cells become determined. If you take potentially muscle cells and put them in the neural region then they will still develop as muscle cells (and you’d have one screwed up organism). OK, it doesn’t have a beating heart (lots of life lack hearts. Besides, your heart beats after death so that’s not a very good measure of life) and it doesn’t have a functioning brain (plenty of organisms get by without one) and couldn’t survive on its own (an infant probably couldn’t survive on its own), but that’s the point where the cells ‘know’ what they are going to become, that’s when it all gets organised.
There isn’t really a way to define when something goes from non-living to living, development is a gradual process. But humans like to group and define things and I figure that there is as good as anywhere.
So, I guess that means that I’m a murderer, I killed Graeme.
I’ve been so busy with Uni. I’ve pretty much limited my arting time to practically nothing and it’s driving me crazy because I have so many plans. I’m only just keeping up with lecture summaries and I haven’t even started to get assignments and tesst yet. I’m getting them very soon, all at once. There’s no way I’ll be able to keep up with everything.
I finally got around to taking photos of the jewellery I made in that short class I took on the holidays. Click on it for a better look.
Mum made the pink beads on the earrings. Aren’t they cool? I love mum’s beads, I want to keep them all to myself. And mum got some enamel so she’s been playing around with they and they create some really cool looks.