Answer:
Chromatin is responsible for gene expression.
Explanation:
Chromatin is responsible for gene expression because chromatin contains DNA that has all information about genes. chromatin controls the gene in order to form encoded products. DNA in chromatin send information to the RNA to produce specific types of proteins that are needed by the organisms for its growth and development so in that way the genes can be expressed in the organism.
I guess that is:
Within the capillaries of the lungs, gases are exchanged by diffusion; O2 diffuses from the alveolus to the bloodstream and CO2 diffuses from the bloodstream to the alveolus.