A student uses two bags of cards to model human fertilisation.
| bag | cards in the bag |
|---|---|
| egg-cell bag | X cards only |
| sperm-cell bag | equal numbers of X cards and Y cards |
For each trial, the student selects one card at random from each bag. Both cards are returned to their bags before the next trial.
State which bag represents the gametes that determine the biological sex of the offspring.
Give the sex chromosome combination and the biological sex of the offspring for each pair of cards selected.
| egg-cell card | sperm-cell card | sex chromosome combination | biological sex |
|---|---|---|---|
| X | X | ||
| X | Y |
Calculate the probability that both of two consecutive trials represent female offspring.
71 exam-style questions on Edexcel GCSE Biology 3.3 Inheritance, covering 3.3.1 Gregor Mendel and the basis of genetics, 3.3.2 Alleles and inherited characteristics, 3.3.3 Monohybrid inheritance, 3.3.4 Determination of sex at fertilisation, 3.3.5 Outcomes from monohybrid crosses, 3.3.6 Inheritance of ABO blood groups, 3.3.7 Inheritance of sex-linked disorders, and 3.3.8 Multiple genes and phenotypic features. Each one has a worked solution and a mark scheme showing where the marks go.