Here's why:

* Recessive genes only express their trait if an individual inherits two copies of the gene, one from each parent.

* If an individual inherits one copy of the recessive gene and one copy of a dominant gene, the dominant gene will be expressed, and the recessive gene will not show up.

Example:

* Brown eyes are dominant over blue eyes.

* If a person inherits one brown eye gene (dominant) and one blue eye gene (recessive), they will have brown eyes.

* The blue eye gene is still present but not expressed.

Let me know if you have any other questions!