In this unit we will use all of the information we have learned thus far to learn about and understand how genes work. We will discuss the scientists who help get us there, how we can determine what traits may be inherited, and how to trace this information in a family. Finally, we will learn about how this information is currently being used in the world today!


At this point we are very familiar with what a chromosome is. Humans have 46 chromosomes, or 23 pairs of them, in each somatic (body) cell. It is now time that we take a step back and focus on the segments of DNA within our chromosomes called genes. Our genes code for our specific traits and proteins-remember that all of this information lies in our DNA!

Gregor Mendel is the "father of genetics" because he is the one who studied and taught us all of our basic genetic principles. His work with pea plants laid the foundation for all that we know today. When we look at traits we see that they are actually inherited in different ways, so it is important to understand each "mode of inheritance" when studying this. You will be required to know the following: complete dominance, incomplete dominance, co-dominance, multiple alleles, and sex-linkage. All of this information can be used with punnett squares so that we can trace the probability of the inheritance of specific genes/traits.

Beyond punnett squares we can trace traits through pedigrees. There are additional tools to help us study traits that run within a family, and can also be used as a method of prediction. We will wrap up the unit studying some genetic disorders and how we manipulate DNA.

Punnett Square Example
The above punnett square shows a monohybrid (one trait) cross following complete dominance. The predicted offspring results would be:
Genotype: 1 AA, 2 Aa, 1aa
Phenotype: 3 Tall, 1 short

Pedigree Example:


Student Work:

Summary Videos
Intro video-Heredity

Genetics Terminology

Punnett Squares -Complete Dominance

Punnett Squares-Incomplete Dominance and Co-Dominance

Summary Videos for Labs
The following links will click you to information and videos for labs we do in class on important concepts. Whether you need a review or to make it up, click below for help!

Pipe Cleaner Babies Lab 1-Explanation

Pipe Cleaner Babies Lab 1-make up for absences

Pipe Cleaner Babies Lab 2-Incomplete and Co-Dominance

Pipe Cleaner Babies Lab 3-Multiple Alleles: Mom is heterozygous type A and Dad is type O for cross one. For cross 2, mom is type AB, dad is type O.