Microscope Answers

by Deb on August 27, 2011

Microscope Answers

If you haven’t tried the Microscopes Quiz, close your eyes and click back.

1.     Archaeans are the third domain of life. There are bacteria/blue green algae which are tiny, single cells and have nothing in their cells like nuclei, their DNA floats around free. Then there are eukaryotes like us that can have single or lots of cells and have nuclei and other organelles inside our cells (some of which look suspiciously like they used to be bacteria). Then you have the Archaea, which were only isolated relatively recently.

They were thought to be bacteria because they look fairly similar. However as we’ve got better with analysing metabolic pathways it turns out they’re quite different. This is the chemical reactions they use to make them work, get energy, grow and reproduce. In some ways they are similar to us rather than bacteria, in others they are completely different. They were originally thought to be very rare remnants, but as we’ve learnt more they’ve been discovered everywhere, including in your gut. Have a look at the videos at the bottom.

2.     Buckyballs are properly known as buckminsterfullerene, so you can see why they’re called buckyballs. They are like an incredibly tiny soccer ball with carbon atoms at the corners. Technically buckminsterfullerene has 60 atoms, other sizes of balls or tubes are just called fullerenes. They are an extremely exciting area of chemistry because they are stable but have a range of extraordinary properties, including extreme strength and conductivity.

buckyball

They were named after Richard Buckminster Fuller who was an amazing man in many ways. In this instance, he invented the geodesic dome, which is very useful in building lightweight but strong structures.

3.     Microscopes are, at heart, complicated magnifying glasses. They use several convex lenses to magnify, as shown in this fairly complicated diagram. Basically, when light hits the lens it bends, but because the lens is curved light from different parts of the image bends differently, making it look bigger.

microscope lenses

4.     Nematodes, or round worms, are the most common type of multicellular animal. There are thousands of nematodes in a handful of dirt from your garden 🙂 Over 28 000 nematode species have been named, and that’s just a few. They are found basically everywhere – marine and freshwater, as parasites, in polar and desert regions, up mountains and deep underground.

How’s this for a great description (from p. 472 of Cobb, 1914 Nematodes and their relationships):

“In short, if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes. The location of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain nematodes. Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficient knowledge, in many cases even their species could be determined by an examination of their erstwhile nematode parasites.”

Roundworm

5.     The photo is a micrograph (ie photograph through a microscope) of granite grains lit by polarised light. Polarised light is light that is vibrating in only one plane. When we draw a light wave it goes up and down, because that’s all we can draw on a flat piece of paper. But really it is going in all directions, including in and out and diagonally. Polarised light is like the wave on the paper – it only goes up and down.

Rocks are made up of tiny grains and crystals, usually of several different types of minerals (or chemicals) mixed together. When you shine polarised light through a thin section it goes through the crystals and gets bounced around and can end up going in different directions. This is what causes the different colours, and they can help identify the minerals in the rock.

There you have five different ways the microscopic world is important to us – inside us and shaping life, learning about the earth and important minerals for mining, materials to let us build amazing machines and computers. It’s a big world out there.

And two videos because I thought they were interesting, both about Archaeans from slightly different perspectives.

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