A double-strand DNA break (DSB) occurs or arises when both strands of the DNA duplex are severed, often as the result of ionizing radiation. They are particularly deleterious as the DNA ends can ...

This can make learning to spell the words quite tricky! Watch this short video to see some more examples of silent letter words. Vowel sounds are made by the letters 'a', 'e', 'i', 'o' and 'u'.

A video guide to all the consonant and vowel sounds in the English language. In this series we will be looking at individual sounds in English, giving you a chance to practise recognising and ...