Well , the humans have a closed double circulatory system as the blood passes by the heart twice per one cycle and doesn't leave the blood vessels like in insects.
》Pulmonary circulation : Blood is circulated to the lungs where it is oxygenated.
》Systemic circulation : Blood is circulated through all the other parts of the body where it unloads oxygen.
Oxygenated blood coming from the lungs enters the heart through the pulmonary vein which takes blood to the first chamber it meets ; the Left atrium. Left atrium pumps blood to the second chamber , which is left ventricle and during this time , the semi lunar valves are closed to prevent back flow of blood and the bicuspid valve will be open . Now , the left ventricle is filled with oxygenated blood so it will pump this blood to the whole body via the largest artery which is Aorta.
Oxygenated blood will unload oxygen to cells in need of it and will return back now to the heart as deoxygenated . This deoxygenated blood will enter the heart through superior and inferior vena cava which will take the blood to the third chamber , right atrium . Right atrium will pump blood to right ventricle so the semi lunar valves will be closed during this time and the tricuspid will remain open. Now that the fourth chamber is filled with deoxygenated blood , it will pump this blood through pulmonary artery when the semi lunar valves opens , to the lungs again to be oxygenated once more.
Notice that you have to know exactly the position of the valves that I have mentioned in the heart so that you could understand the blood flow better. You can refer to any heart labelled diagrams in your textbook or the internet.
<span>A head-on shot rarely results in a clean kill, ruins meat, and provides a means for the animal to best detect the hunter. It is difficult to achieve this shot, which often results in the deer hearing the gun and running away (thus, detecting the hunter). Moreover, the shot will cause in a waste of a lot of the meat because of the location rendering it unusable and inedible.</span>
B) b - c - d - a
The chromosomes multiply, line up, are pulled apart by microfilaments, then the microfilaments break down.
Answer:
Newton's first law.
Explanation:
The first law, in which an object moves forward in a straight line unless acted on by an outside force. It describes Inertia it the inherent property of the body due to which it opposes any change in its state of motion or rest. So due to Inertia, Tasha's brother's body moved forward.
Answer: a mutagens d carcinogens b point mutation c frameshift e missense f nonsense
Explanation: Hope that helps!
