I definitely think that some people are accent sponges and other people aren't. You pick up dialects and accents from the people around you when you're learning to speak. This gives you a similar accent to your mum or dad. Accents are, afterall, just imitation. The reason things like this occur, is that if you get a group of people together in one place, the strongest people tend to attract imitation amongst the other people. So if someone has a particular way of speaking, people try and blend in and talk in the same way. So someone with an English accent in America is likely to pick up some of the American accent.

In a plant, you have a leaf which is receiving sunlight and taking in carbon dioxide from the atmosphere to make sugars and some proteins from photosynthesis. The sugars then get redistributed round the plant. How does that actually happen? There are two transport systems in a plant. One of them just works in one direction. Essentially there's a series of long tubes between the roots and the leaves called xylem. These are dead cells which have been waterproofed with a special material called lignin and they have cellulose around them. They are about 0.01 millimetres across, and at that kind of thickness, the column of water that flows into them has a tensile strength stronger than that of steel. As the water evaporates from the leaf at the top end of the plant, it pulls the water up from the root. That's fairly intuitive. But how do the sugars go from the leaf down to the root? Well scientists have wondered about this for quite a long time, and thought that it might be just 'source and sink'. In other words, if you make a lot of something in one place, it tends to move away from where there's a lot of it to where there's not much of it. That's one possibility of how things are moved around. However, there's a second transport system called phloem and these are individual living cells that have individual plates between the cells that act like sieves. They can actually control the direction in which things move in those cells. Although it's pretty sketchy exactly how they know how to control whether something goes up or down, there's very good evidence that it does work like that because plants do distribute things in the right direction according to which way they need it to go. If you kill those cells, the process stops. This shows that it uses energy. That's really the extent of our knowledge at the moment.

If you look at the cells in your body, there's an electrical gradient between the inside and outside of the cell. In other words, the inside of a cell is slightly more negative than the outside. The way cells manage to do that is that they have the cellular equivalent of a revolving door. It picks up three versions of a sodium on the inside of the cell and boots it out, and picks up two potassiums on the outside of the cell and brings it in. Overall, the cell is exchanging three plusses for two plusses, which creates an electrical difference. You can use that electrical difference to do some work for you, such as grabbing something that you want. This all requires energy, and is active transport. Cells are doing it all around your body to transport glucose into your cells. That's how cells like the liver, even though they're stuffed with glucose most of the time, an get even more packed in. I think plants are probably up to the same trick.

Your urine contains lots of waste products including a chemical called urea, which is a by-product of protein. Urine is quite concentrated unless you've been drinking a lot of water. When you put concentrated urine on the ground, it essentially dries out the grass roots like a prune and kills it. Urea is also a rich source of nitrogen, which is a good fertiliser and a boost for the grass when new shoots start to grow. So it kills off the grass, and then causes better grass to grow.

'O' is referred to as a recessive allele. In other words, if you have group O, your cells don't make any markers on their surface. These markers are like little flags that the body uses to recognise them. People who are Group A can be Group A because they have one gene for making 'A' markers, and another gene that doesn't make any markers. So someone can be Group A if they have one gene for A and one gene for O, because you have two copies of these genes. One is from your mother and one is from your father. The other way someone can be group A is if they have two copies of the A gene. If both your parents are Group A, they must have genes A and O each. When a sperm with an O gene in it meets and egg with an O gene in it, you end up with two O genes and blood group O. It's also right that you are the universal donor. You can only receive blood from a person like you: O rhesus negative. Only 15% of the population has this blood. The rhesus factor is an additional gene or flag on the surface of the cell. This is known as the D allele. If you have that, then your cells just make an additional marker. This becomes important is if a pregnant lady is O rhesus negative and has a husband who is rhesus positive. The baby can be rhesus positive and the result is that some of the baby's blood can mix with some of the mum's blood when the baby's born. This can make the mum make antibodies against rhesus blood. That's fine for the first pregnancy, but if you get pregnant again, those antibodies can end up in the baby and cause all sorts of problems. It is normal for antibodies to be passed from mum to baby, wither through the blood or through breast milk. However, if you've produced antibodes to something in the baby's blood, then the antibodies latch onto the blood cells and damage them. That's why you end up with a baby that looks bruised. This is just where the blood cells are breaking down. Luckily, this can be dealt with by giving the mother a dose of antibodies at birth. Overall, your blood is so useful because it has no markers on it, so when it's put into someone's body, they have nothing to latch onto.

Their shells are actually an extension of their body, so they can't crawl out of their shell. The shell is anchored by the ribs on the inside of the shell. It's made of keratin, which is the same stuff that hair, nails and horns are made of. Inside that shell, a turtle's body is very muscular and is suspended from the ribcage. A turtle's neck can form a s-shape either sideways or vertically. When a turtle wants to pop his head in and out, they either fold their neck sideways or fold it long ways and upwards.

It's a very good point. If you look at your fingers, you'll see that there are lots of little ridges. If you lick your finger, you create a little area of dampness on the tip of the finger. When you press it hard onto a surface, you squeeze water out in exactly the same way as if you were squeezing a sucker onto a window. You get this attraction of the water locking onto the molecules on the surface of the page and locking onto the ridges on your finger and it gives you a bit more grip. However, when you've got your kitchen floor with a big puddle on it, what you end up with is a very thick layer of water. You have a layer of water coating your foot, a layer of water coating the floor and a layer of water between the two. You end up with a layer of water sandwiched between two other layers of water and that it very slippery. This is exactly the reason why tyres on cars have tread. The tread means that your tyre squashes the water out through the tread pattern and stops you getting this slippery sandwich and gives you a better grip on the road.

It's actually not as difficult as it sounds. You have this amazing system on the front of your eye ball called the cornea. Just beneath that is the lens, which helps to tweak the process. However, the cornea alone has this amazing focusing ability and is there to focus light precisely onto your retina. All you have to do is look with your camera in the front of the eye and shine a light so you can see what's happening inside the eye. The front of the eye, the cornea and the lens, does the rest of the job for you. It focuses the light straight onto the back of the eye. If it's not quite in focus, you can adjust the camera to make the picture clearer. If you look on the back of the eye, you'll see this white patch. This is where the optic nerve comes into the back of the eyeball and all the nerves from the retina bundle together. The reason they are in one bundle is so that they don't take up that much space in the back of the eye, which would of course create a blind spot. The other way to take a picture of the back of the eye is to inject a glowing yellow dye called fluorescein. When this flows into the blood vessels in the back of the eye, it makes them glow when you shine a certain wavelength of light on them. This shows you where the blood vessels are.

It's an emulsion. The oil which makes the delicate flavours of ouzo dissolves very nicely in alcohol, but it doesn't dissolve very well in water. When you add water, it binds to the alcohol, which dissolves well in water. The oil eventually stops binding to the alcohol and starts hanging around with other oil molecules. These little aggregations of oil in the water make the drink turn milky white. If you were to zoom in with a very powerful camera, you would see these tiny globules of oil being completely surrounded by water molecules. This is exactly how emulsion paint works, where you have globules of oily paint molecules surrounded by water.