Answer:
a. When a fetus is 13-15 weeks old
Explanation: is correct
The answer is Cutaneous Respiration. It is respiration through the surface of the skin. Cutaneous Respiration is used to supplement respiration alongside the use of their lungs. Cutaneous respiration<span> occurs primarily as a means of carbon dioxide exchange, with the majority of oxygen exchange occurring in the </span>lungs<span>. Frogs </span><span>take up most of their oxygen through </span>cutaneous respiration<span>, even if they possess </span>lungs<span>.</span>
Answer:
it is colour less their is no colour ...
<span>The plasma membrane is phospholipid bilayer. The layers are two and are continuous flat sheets. They have proteins and cholesterol embedded in them, for facilitating the transport of compounds and maintanng fluidity. The lipid bilayer is both hydrophobic and hydrophillic. </span>
Answer:
When you eat, food passes from the throat to the stomach through the esophagus. A ring of muscle fibers in the lower esophagus prevents swallowed food from moving back up. These muscle fibers are called the lower esophageal sphincter
Explanation:
