The Grand Canyon, the Grand Canyon is constantly eroding and getting bigger and deeper, it is so deep is called the Grand Canyon. It has been a historic landmark for decades!
Answer:
When oxygen levels in the blood decrease, the respiratory center sends signals to the diaphragm to increase the rate at which it contracts and relaxes.
Explanation:
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Answer: C) Algae</h2>
Explanation:
By process of elimination:
- moss is a plant belonging to the Bryophyta division. It is not a protist
- paramecia are animal-like protists that don't generally photosynthesize
- protozoans feed on organic matter such as other microorganisms or organic tissues and debris (not autotrophic)
- This leaves Algae, which are autotrophic protists.
Answer: B. pressure changes in the thorax
Explanation:
The veins are the blood vessels which returns the deoxygenated blood from all the tissues and cells of the body back to the heart. The ventricular systole, venous valves, activity of the skeletal muscles and neural control over venoconstriction all influence the movement of the blood in the venous.
The pressure changes in the thorax occurs due to inspiration and expiration. During the process of inspiration, the diaphragm below the lungs contracts and moves downward while the muscles of the ribs pulls downward. When the size of the thoracic cavity increase the air pressure inside the cavity decreases and vice-versa. The pressure inside the thoracic cavity is not related with the movement of the venous blood as it regulates the exchange of the gases not the blood.