This is actually true. There are two types of suncream, some with chemicals and some with zinc. The chemical-based suncreams are the most commonly available ones, the ones which absorb into the skin and don’t leave a thick white layer behind. The chemicals in these creams are quite unstable, and are broken down by exposure to sunlight (in this way, the suncream absorbs the radiation, instead of your skin.) This also means that they will break down over time, and last year’s cream will not be as good at protecting you from the sun as a new batch would.

When the body dies, your cells don't immediately stop your metabolism winds down over a short time. Tannig involves production of melanin in cells in the skin, and so would probably continue for a little while after death.

Not any more. Since scientists found out that BSE can be spread by blood transfusions, they have been ‘leucodepleting’ all transplant blood in the UK. When you give blood, they use a special technique to remove all the white blood cells and leave only the red blood cells, which are safe to transfuse. Human red blood cells don’t have a nucleus (unlike birds) and therefore do not contain any DNA. So transfusions given recently will definitely not contain any of the donors DNA.

In the 60’s, blood was not separated out like this, but we did realise that you could transfer viruses through transfusion like this, so the blood was irradiated. This destroyed the DNA, but left the red blood cells intact.

This could be a manifestation of Oral Allergy Syndrome. If you suffer from hayfever, an allergy to pollen, you may find some of the same substances in the plant as you would find in the pollen. When you eat the plant, your mouth is exposed to the same things as you would in the pollen, and so you have a miniature allergic reaction in your mouth. The symptoms are pricklyness, swelling, itchyness, even an itchy sensation on the inside of your ears! The Numbness in your tounge would well be the celery prompting this oral allergy. Celery is in the same family as birch, so if you are allergic to birch pollen, you may well get this reaction to celery.

When if you’re chewing something like chewing gum and you chew too hard, sometimes you can overwork the muscles and they can ache in the same way as if you did a lot of digging you might make your back or shoulders ache.

The other thing to consider is that there is a joint where the mandible, or jaw meets the skull, called the temporomanibular joint. That can actually end up being sore in some people, and then its called TMJ dysfunction.

Normally, the current passing through the wires in your house does not generate enough heat in order to make them react with oxygen. Most wiring is copper, and you need to get copper to quite a high temperature to make it react with oxygen and produce copper oxide. This shouldn’t happen unless the wiring actually catches fire.

However if the wires get wet dissolved oxygen can react with the copper much more easily, so they will oxidise even at normal temperatures.

(We put this question to Dr Howard Ring, a Neuroscientist from Cambridge University)

You should be perfectly safe. There’s probably far more capacity in your brain to put stuff in than you will ever use, although recalling it can be difficult, there’s been research recently demonstrating that recall is the tricky bit, but that there’s far more in there than you might have thought.

(We put this question to Professor Nick Craddock, a Neuroscientist from Cardiff University)

Well the answer to this question is that we’re not sure. Certainly, things that influence neurotransmitter systems that can alter mood or create anxiety feelings. The amino acid tryptophan gets turned into 5-hydroxy-tryptomine, which is also known as serotonin, the brain’s feel good chemical. If your diet is deficient in tryptophan this can lead to depression. One of the reasons people like to binge on chocolate is that chocolate can raise serotonin levels. Undoubtedly, food can have an effect on mood, but we’re not sure to what extent.