Science (086) — AI-generated practice question

In sexually reproducing organisms, a child receives one copy of each gene from the father and one from the mother, making two copies per trait in the offspring. For this to work correctly, each germ cell (sperm or egg) must carry only one copy of each gene. If germ cells carried two copies, the offspring would receive four copies per trait, violating Mendel's principle that sexually reproducing organisms have exactly two copies of genes controlling each trait.

Source: Chapter 8, Section 8.2.2

---

• Examiners want you to link germ cell formation → fertilisation → two copies in offspring as a logical chain.
• The key Mendelian idea: sexually reproducing organisms have two copies of each gene (one paternal, one maternal). This only holds if each gamete contributes exactly one copy.
• Avoid over-explaining; two tight sentences covering "why one" and "what goes wrong with two" is enough for 2 marks.