IMO Practice Test — Principles of Inheritance and Variation

A tall pea plant could be either TT or Tt. A test cross with a dwarf (tt) plant identifies it because if any dwarf offspring appear, the tall parent must be:

New combinations such as round-green and wrinkled-yellow appearing in the F2 of a dihybrid cross are explained by:

Crossing two pink snapdragons (Rr × Rr) gives a phenotypic ratio of:

A colour-blind father and a normal (non-carrier) mother have children. Their daughters will most likely be:

Blaming the mother for the sex of a child is biologically wrong because the egg always carries an X, so the sex is decided by whether the sperm carries:

In regions where malaria is common, the sickle-cell allele can persist because carriers (heterozygotes) have:

Crossing over reduces linkage between two genes more often when the genes are: