A human egg is fertilised by a sperm carrying a Y chromosome. The embryo grows to eight cells by mitosis. Each cell has one nucleus, and all divisions occur normally.
What is the total number of X chromosomes across these eight nuclei, and which parent supplied them?
Eight X chromosomes, all originating from the mother.
Eight X chromosomes, all originating from the father.
Sixteen X chromosomes, all originating from the mother.
Sixteen X chromosomes, all originating from the father.
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.