Genetics · Module 6 · Chromosome mutations

Chromosome Mutations Lab

Run meioses in inversion and translocation heterozygotes and watch the gamete tally build; practise rearrangement, karyotype and chromosome number problems with animated worked solutions; match abnormalities to their pictures and consequences; and work through real cases. Nothing here is graded.

Part 1: Meiosis Bench

Gamete tally
Gamete typeCountObservedExpected

Simplified model for learning. Inversions: four chromatids, at most one crossover per meiosis, a dicentric bridge breaks at a random point and an acentric fragment is always lost. Random mode puts a crossover inside the loop with the chance you set; otherwise half the meioses get a crossover outside the inversion. Translocations: each line stands for a pair of sister chromatids, crossovers are not shown (in the arms they swap alleles but do not change balance), and random segregation uses alternate 50 percent, adjacent 1 40 percent and adjacent 2 10 percent; real frequencies vary. Robertsonian random mode treats the three segregation patterns as equally likely, which overestimates real risks. Gene letters are made up.