In fact, there are typically many of these "books", called chromosomes.

Within cells DNA is organized into long structures called chromosomes.

Mendel's work was then correlated with what was being called chromosomes within the nucleus of each cell.

Each human cell contains structures called chromosomes, which carry the genes (DNA).

Many genes together make up larger structures within the cell called chromosomes.

Genes themselves are inherited in long chains called chromosomes, made of the chemical DNA.

They're partners with some skinny guys called chromosomes, and the two of 'em show up everywhere you look, once you've got your eyes focused just right.

Still other genetic disorders are due to problems with the number of packages of genes called chromosomes.

Some special chromosomes called limited chromosomes are present in certain stages.

Human cells package their genetic instructions in rod-shaped storage devices called chromosomes.