The section of a chromosome that carries information specifying a particular characteristic of an organism is called a gene.

Here's a breakdown:

* Chromosome: A long, thread-like structure made of DNA that carries genetic information.

* Gene: A specific segment of DNA on a chromosome that codes for a particular trait or characteristic. This can be anything from eye color to susceptibility to certain diseases.

Think of a chromosome like a book, and a gene like a single chapter in that book. Each chapter contains instructions for a specific aspect of the organism's development or function.