Question

In steps 4 and 5, you reversed the process. You were shown the parents and offspring above. You did a
to identify the genotypes of the parents

Answer 1

You did a test cross to identify the genotypes of the parents.

Briefly:
- A test cross is crossing an individual with a dominant phenotype to a homozygous recessive individual and using the offspring phenotypes to infer the unknown parent’s genotype.
- If any offspring show the recessive phenotype, the unknown parent must be heterozygous. If all offspring show the dominant phenotype (over many offspring), the parent is likely homozygous dominant.
- More generally, you can “reverse” a Punnett square: use observed offspring ratios/phenotypes to deduce the parental allele combinations.

If you paste the parent/offspring data you were shown I can walk through the exact inference and any caveats (sample size, linkage, incomplete dominance, etc.).