Answer: a. Increasing the surface area for diffusion
Explanation:
When the air is inhaled through the nostrils, the air containing the oxygen the air diffuses inside the alveoli. The alveoli are the tiny sacs where air enters and exchange of gases takes place. From the alveoli the oxygen enters into the blood stream. The oxygen is utilized by the cells for respiration. The increase in network and number of the alveoli will increase the surface area for the diffusion of oxygen and hence, will speed up the respiration process.
answer: The raw materials of photosynthesis, water and carbon dioxide, enter the cells of the leaf, and the products of photosynthesis, sugar and oxygen, leave the leaf.
Explanation:
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DNA can illustrate that evolution has occurred since in the process of natural selection advantegeous genes or traits have been selected to pass on through generations and further more evolve as long as the species survies and is successful in reproducing.
The lymphatic vessels are thin-walled valvular structures, composed of lymphangions, which carry the lymph from the tissues, via the lymph nodes, to the bloodstream. For this reason, they are analogous to veins and venules.
The lymphatic network is present throughout the body with the exception of the central nervous system and non-vascularized tissues.
It is separated in two circuits: one for the upper right quarter of the body, and one for the rest.
The lymphatic channels join together to form lymphatic vessels more and more voluminous.
Finally, The lymph is drained by two large collectors:
* The right lymphatic canal
* The thoracic duct.
All lymphatics thus end up in the upper vena cava system by two separate circuits.
