Free Biology Lesson Plan Examples for 9th Grade Learners

The basic laws of inheritance are important in understanding patterns of disease transmission. The inheritance patterns of single gene diseases are often referred to as Mendelian since Gregor Mendel first observed the different patterns of gene segregation for selected traits in garden peas and was able to determine probabilities of recurrence of a trait for subsequent generations.

This biology lesson provides a basic introduction into Punnett squares. It explains how to do a monohybrid and a dihybrid cross.

The law of segregation states that every individual possesses two alleles and only one allele is passed on to the offspring. The law of independent assortment states that the inheritance of one pair of genes is independent of inheritance of another pair.