In humans the sex chromosomes of a female are XX and of a male are XY. Which statement explains why about half of all babies born are boys?
Half of the mother's egg cells carry a Y chromosome
Half of the father's sperm cells carry a Y chromosome
Half of the mother's egg cells carry two X chromosomes
Half of the father's sperm cells carry two X chromosomes
76 exam-style questions on AQA GCSE Biology 6.1 Reproduction, covering 6.1.1 Sexual and asexual reproduction, 6.1.2 Meiosis, 6.1.3 Advantages and disadvantages of sexual and asexual reproduction, 6.1.4 DNA and the genome, 6.1.5 DNA structure, 6.1.6 Genetic inheritance, 6.1.7 Inherited disorders, and 6.1.8 Sex determination. Each one has a worked solution and a mark scheme showing where the marks go.