Question

The mating of two curly-haired brown guinea pigs results in some offspring with brown curly hair, some with brown straight hair, some with white curly hair, and even some with white straight hair.
This mating illustrates which of Mendel's Laws? Depict the mating with the help of a cross
Class 10 Biology

Answer 1

Answer:  Let us represent fur colour by 'B' (dominant) and 'b' (recessive) and hair by 'C' (curly) and 'c' (straight).  

It is given that a guinea pig with straight hair and white fur (bbcc) is crossed with a guinea pig with brown fur and curly hair (BBCC or BBCc). The F1 progeny had brown fur; hence, brown fur is dominant over white fur and curly hair is dominant over straight hair.  

Since, straight hair also appeared in the F1 progeny, the genotype of the parent with brown fur and curly hair can only be BBCc. The cross can be represented as follows;

This depicts the law of dominance