<span>Streptococcus is a genus of coccus (spherical) Gram-positive bacteria belonging to the phylum Firmicutes[3] and the order Lactobacillales (lactic acid bacteria). Cell division in this genus occurs along a single axis in these bacteria, thus they grow in chains or pairs, hence the name—from Greekstreptos, meaning easily bent or twisted, like a chain (twisted chain). Contrast this with staphylococci, which divide along multiple axes and generate grape-like clusters of cells.)</span>
If a pair of Organisms are capable of producing fertile offspring in nature they must belong to the same species
The exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli. You can see more in wikipedia, or here: https://www.merckmanuals.com/home/lung-and-airway-disorders/biology-of-the-lungs-and-airways/exchanging-oxygen-and-carbon-dioxide
