In mammals, birds and some reptiles, sex is determined by sex-specific chromosomes.  In mammals, the sex-determining chromosomes are called X and Y, and only males have both.  In birds and reptiles, these chromosomes are called Z and W, and only females have both. How are these related to one another and to the rest of […]

World Tourism Day WORLD TOURISM DAAAY! Come and discuss with us, what countries have you been to, what did you do there, did you experience culture shock, what are your […]