Answer:
When you sit on a plane for 6 hours without moving, blood accumulates in your veins, and the moment you get up, gravitational forces affect venous return, cardiac output, blood pressure, and venous pressure. That way, when you're sitting on a plane, the gravitational force is the same at the upper and lower extremities, such as the chest, abdomen, and legs, causing venous blood pressure and volume to be evenly distributed throughout the body. However, when one gets up, one becomes dizzy because of abnormal regulation of blood pressure. This is because gravity causes blood to accumulate in the lower extremities (veins of the legs and trunk). This lowers the blood pressure and the blood that the heart pumps. By causing blood to accumulate in the lower extremities, and as venous compliance increases, the veins expand with blood that causes the volume of blood to shift in the veins. This increases the volume and venous pressure in the lower extremities when standing. And the volume of thoracic venous blood is less and less central venous pressure. This leads to a decline in stroke volume. Cardiac output and mean arterial pressure also decrease as left ventricular stroke volume decreases, reducing pulmonary venous return. Decreased standing blood pressure, referred to as orthostatic or postural hypotension. Thus, lowering blood pressure decreases cerebral blood flow, which means less range of blood in the brain causing dizziness.
Explanation:
Autotrophs are the producers in the food chain, meaning they create their own nutrients and energy. Kelp, like most autotrophs, creates energy through a process called photosynthesis. An autotroph is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals
RNA<span> (Ribonucleic Acid) is synthesized in the nucleus and is very similar to </span>DNA<span>. The synthesis of </span>RNA<span> also involves the use of bases, but in </span>RNA<span> synthesis no thymine (T) is </span>used<span> but uracil (U) is </span>used<span> instead. ... The synthesis of </span>RNA<span> from </span>DNA<span> is called transcription (the </span>DNA<span> is transcribed into </span>RNA<span>).</span>
The concept of spontaneous generation was disapproved by Louis Pasteur. He did this by boiling liquid with proteins and other nutrients in S-neck flasks and usual flask to eliminate all the microbes present. In the usual flask the liquid showed modifications when coming in contact with air, and in S-neck flask, there was no change, as microbes were not able to get within the S-neck flask.
When the S-neck was removed, a change in the liquid was observed as microbes were able to penetrate the liquid. Pasteur demonstrated that it was not the air itself, however, the particles present within it that exhibited microorganisms.
<span>We are taught that modern scientists are driven only by reason and facts. It was only early scientists like Galileo who needed to fear the reaction to their radical views. Neither of these beliefs is true. The reaction to Alfred Wegener's Continental Drift Theory demonstrates that new ideas threaten the establishment, regardless of the century.</span>
