Could the Beckhams have a girl?

Victoria Beckham is pregnant but is it possible that she might have a girl this time? This resource takes students through what we mean by sex chromosomes, what happens to chromosomes during fertilisation and sex cell production and finishes with a Punnett square that students can use to tell the Beckhams what the probability of their baby being a girl is. For more topical teaching ideas and resources please visit the blog.