The segment of a DNA molecule that carries the instructions for producing a specific trait is called a gene.

Here's a breakdown:

* DNA (Deoxyribonucleic Acid): The molecule that contains the genetic instructions for building and maintaining an organism.

* Gene: A specific sequence of DNA nucleotides that codes for a particular protein or functional RNA molecule. These proteins and RNA molecules are responsible for carrying out various functions within the cell and ultimately contribute to the organism's traits.

Example: A gene might carry the instructions for producing the protein that determines eye color. Different versions of this gene (called alleles) might lead to different eye colors (e.g., blue, brown, green).

So, genes are the fundamental units of heredity, and they hold the blueprints for life!