Question: As, you mentioned earlier, how can plants defend themselves against changes of weather? And how can bugs survive in extreme conditions? Also, what cause jetlag?

Sarah Martin answered on 19 Jun 2012:

Hi rhea! Thanks for asking again! Right, here it goes:

– Plants renew themselves continuously, so all the time they are making new proteins and other molecules, and taking old ones apart. So every day, about 1/10th of a plant will be all new molecules, but put back in the same place, so you wouldn’t notice! This means that when there is a sudden change in weather happens, they just continue taking out the molecules but don’t replace them with the same ones. So if it suddenly becomes dark, they won’t replace the bits they need for photosynthesis, because there’s no point – they’ll wait until it’s light again. And if it’s suddenly hot, they’ll make lots of molecules that make them heat restistant. Last year I worked out a way that we can measure how fast and when each protein in a plant is replaced. Ask again if you want more details!

– Bugs are amazing. There is one bug that we found on a lava flow in Iceland, and thought that was a strange place for it to be able to live! But since we started studying it, we also found it can live in water, in dust in the air, on human skin, and even in our lungs! It’s called Micrococcus luteus if you want to check it out yourself. It survives just about everywhere, and is bright yellow. The trick is that it has a really thick skin, so no matter what happens around it, it can keep the inside separate from really dry or wet surroundings and just keep going. The other thing is that it has adjusted its chemistry to work in high heat and in very cold! You see, human chemistry can only really work in a body temperature between 34 and 40 degrees centigrade, which is quite limiting if you think about it!

– Jetlag is caused when your body clock gets confused. Every organism we’ve looked at so far has its own body clock – biological rhythm that helps it work out when to get up and when to go to sleep, when to eat and when to rest. Plants also work out when to get all their leaves ready for photosynthesis before the sun rises that way! When we travel to a different time zone, our body clock still expects things to happen every 24 hours – but if we’re not in Australia or America, we’ll have to change to what people do there instead, so we may have to put our body clock off by 10 hours or more, and then it’ll take a few days to work out when to wake you up and when to expect food and so on.
Here’s an Australian video that explains all about it!
http://www.abc.net.au/catalyst/stories/2351893.htm

All clear?

Thanks! 🙂 Sarah