The gene is considered the basic unit of inheritance. Genes are passed from parents to offspring and contain the information needed to specify physical and biological traits. Most genes code for specific proteins, or segments of proteins, which have differing functions within the body. Humans have approximately 20,000 protein-coding genes.
The above definition is from the National Human Genome Research Institute. Learn more about genes here.
Here are some experiments developed for middle school student by the University of Arizona BioTech Project:
Cootie Genetics: In this activity students will simulate the work of Gregor Mendel to investigate how traits are inherited. Students mate "Cootie" organisms with different true breeding traits and explore trait behaviors (dominant, recessive) and trait probabilities- while having fun! This lesson should be introduced before genetic terminology, DNA and/or Punnett Squares. [Three to four 50 minute class periods]
Click here to access the Cooties web site.
[Student Guide] [Materials Guide