Red blood cells exchange carbon dioxide for oxygen
The answer would be Linnaeus primarily used physical characteristics.
A lot of DNA is structural and doesn't pertain to any genetics while it only takes a small change to change something big. DNA mainly uses 4 different chemicals to change itself, not giving a lot of variety. Most animals share around 98% of the same dna with each other. Humans share 50% of their DNA with a banana. Pretty much everything shares the same double helix design as well. So a lot of genetic code looks similar.
The correct answer is by facilitated diffusion.
The procedure of continuous passive transport of ions or molecules through a semi-permeable membrane with the help of particular transmembrane integral proteins is known as facilitated or passive-mediated transport or facilitated diffusion.
It is a modification of osmosis incorporating a proteinaceous channel via which an extracellular solute can enter a cell in the absence of energy.
Humans, when exhaling release carbon which helps them to make sugar, and as a biproduct plants release oxegen which humans inhale.
