The answer is C, hope this helps
Answer: The atom of carbon is able to form macromolecules because it has only four electrons in its outer shell. This is the reason why it can bond with four other carbon atoms. The bonds that it forms with other carbon molecules are very stable.
Explanation: I did my research and i also took Science class. :)
Hope this Helps :).
Answer:
Hemoglobin.pulmonary artery.
Explanation:
1. about hemoglobin.Hemoglobin is the protein inside red blood cells. It carries oxygen.
2. about pulmonary artery.The pulmonary artery is a big artery that comes from the heart. It splits into two main branches, and brings blood from the heart to the lungs. At the lungs, the blood picks up oxygen and drops off carbon dioxide. The blood then returns to the heart through the pulmonary veins.
3. There exist a concentration difference of carbon dioxide and oxygen inside the alveoli and capillaries due to which the diffusion of the two gases takes place. The carbon dioxide moves from the blood to the alveoli sac and the oxygen moves from the sacs to the blood.
It started in 1798, to the 1800. This period is when the human population began to grow at a faster rate then any other time in history.
