The set of instructions for making proteins that are coded in DNA and passed from parent to offspring each generation is called genes.

Here's a breakdown:

* DNA: The molecule that contains the genetic code. It's like a blueprint for an organism.

* Genes: Specific segments of DNA that provide the instructions for building and maintaining an organism. These instructions are carried in the sequence of DNA's building blocks (nucleotides).

* Proteins: The workhorses of the cell, carrying out a wide range of functions, from structural support to enzymatic activity. Genes provide the instructions for building these proteins.

So, genes are the fundamental units of heredity, passed down from parents to offspring. They determine everything from eye color to disease susceptibility.