Inheritance

However, different characteristics are inherited at the same time…you inherit height and eye colour, freckles and dimples, hair colour and tongue rolling….

Dihybrid crosses are those where we consider the inheritance of two characteristics at the same time.

This covers Mendel’s Third Law:

3. The Law of Independent Assortment

–Factors of a trait separate independently of one another during gamete formation. Genes found on separate chromosomes are inherited independently of each other.

–Mendel had observed that the seeds of his pea plants varied in several ways – among them, whether the peas were round or wrinkled and whether they were green or yellow. 

–He did monohybrid crosses on both characteristics, but then decided to look at how they were inherited together….

•From his monohybrid trials, Mendel had discovered that the allele for yellow colour was dominant to that for green.

•He had also found that the allele for round peas was dominant to the allele for wrinkled peas.

•Starting with individuals that were homozygous, either for both dominant characteristics or both recessive characteristics, he set off breeding again…