Question

what do the letters in this model represent?
nitrogen bases
karyotypes
chromatin
chromosomes

Explanation:

The image shows the structure of DNA with labeled components. Cytosine, Thymine, Guanine, and Adenine are types of nitrogen bases. In the DNA double - helix model, these nitrogen bases pair up (Cytosine with Guanine, Thymine with Adenine) to form the rungs of the DNA ladder.

Answer:

Nitrogen bases