Thursday, 3 April 2014

Chemical Warfare

It feels just like yesterday that I wrote my previous post but then I realised  we're in April now! It's crazy how fast the days are passing.

We had a bit of drama today on the road outside our house. Our neighbour down the road has decided to build a new house in his  paddock directly opposite us. Which means a new concrete driveway had to go in. They've boxed it all up in the last couple of days, but today had some road workers holding up traffic as the concrete truck took up the whole road. It was interesting because there is a big sweeping bend outside our house, and the speed people go around it! Ideally 45km/h is the best speed to go around it, but generally drivers take the corner extremely fast and end up in the middle of the road, or on the other lane! Mum and I decided that the lollipop guys should stay full time and slow the traffic down!

Biology today was a fun affair, and for a change in relation to school work I'm not being sarcastic! How great is that?! I'm doing the topic on plant and animal responses to their external environment. There was a mix up with the booklets which meant I had to begin on the animal one, the second in the topic. So it hasn't been all that fun because there's been a lot of things that I haven't fully understood and they haven't explained much on. But I now realise this was because it was covered in the first book on plants.
     Much to my surprise, learning about plants is actually really cool! They talk a lot about how plants are the beginning of the life cycle, they're the ones eaten first etc etc etc. But then they go on to say that, well, plants don't actually enjoy being eaten all the time and they've quite seriously got a fair amount of ammunition up their, um, stems.
     For instance, there are some plants that produce volatile chemicals. So when they're attacked by, say, a caterpillar, the chemical is released into the air which then attracts predators to attack the caterpillar. In this case dragonflies come to feed on the caterpillar, or wasps will lay their eggs inside the caterpiller, which in turn will save the plant.
     Then there are other plants such as the Chrysanthemum that have pyrethrins in their leaves. This is nasty, toxic stuff which prevents insects from eating the leaves and eventually kills them. However it does go on to explain how some caterpillars developed an enzyme to detoxify the pyrethrins, thus they could carry on eating the plant. But wait, the Chrysanthemum can go one better and produce another chemical to knock out the protective enzymes! So much chemical warfare!!!

Later on I read about plants of the same species being able to communicate with each other. Yeah, I know right? I thought trees only talked on Lord of the Rings. Apparently not!
     They say that when under attack, a tree, such as a Willow, will release volatile chemicals which are then picked up by the trees of the same species. The other trees understand the warning of being eaten by herbivores, so they also start producing the chemical, which induces the production of another chemical which protects the tree from further attack.
     Other trees produce a chemical to make their leaves unpalatable, so grazers like the Giraffe only stop for a bite, before continuing on to the next tree, which has in fact been pre-warned by its neighbour! Pretty cool huh? Imagine if humans communicated in the same way....It'd certainly save for awkward conversations!

In the relation to plants not being too keen on being eaten, I'm going to squirm a bit next time I eat some form of plant, or pull some leaves of silverbeet for the chooks. I can just imagine hearing it scream in anger and start firing heaps of nasty toxic juices at me! They say humans are bad for being the ultimate predator and killing everything, but when you think about it, plants are at the beginning of the life cycle and they're pretty darn evil and twisted. It's no wonder we're like we are, we have to protect ourselves! As the booklet says, plants are pretty crazy chemists!

This form of biology is so much different from previous levels, for instance, the answers don't show just the one answer. They have examples for Achieved, Merit or Excellence answers. And unlike level 2, they don't ramble on about just DNA and genes in every topic, this one for instance has completely moved on from general photosynthesis. Don't get me wrong, I love learning about the genetics side of biology, but it's nice to get something different. I even think there is a topic on human evolution...? That'll be a little out there to study I think...I'm happy with plants evolving to suit their environments, but humans? Yeah..Nah.
     I'm happy with how much I've done over the past couple of days though, just one more chapter in the first booklet, and two more in the second booklet. Of course I've got the Teacher Marked Assessments at the end and then that will be one external topic, eventually worth five credits (five, for such an easy topic?!) done and dusted.

1 comment:

  1. A very curious post today, especially on the chemical reaction of plants.