A cleft chin is a physical genetic trait where a person has an indentation in the center of their chin. This trait is caused by a dominant allele, represented by CCC. A person without a cleft chin has a smooth chin, which is the recessive phenotype caused by the allele ccc.
Complete the table below by identifying the missing genotype name, alleles, or chin type (cleft or smooth) for each row:
| Genotype | Alleles | Chin Type |
|---|---|---|
| homozygous dominant | (i) | cleft |
| (ii) | cc | (iii) |
| heterozygous | Cc | (iv) |
The table below lists possible genetic crosses between parents. Complete the table by determining the probability (as a decimal) of each cross producing a child with a cleft chin. One has been done for you.
| Parent genotypes | Probability of child with a cleft chin |
|---|---|
| Cc×CCCc \times CCCc×CC | (v) |
| Cc×ccCc \times ccCc×cc | 0.5 |
| Cc×CcCc \times CcCc×Cc | (vi) |
66 exam-style questions on Edexcel IGCSE Biology Inheritance. Each one has a worked solution and a mark scheme showing where the marks go.