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The DNA exists as a double helix. It consist of two intertwined polynucleotide chains that run anti-parallel (in opposite directions) to each other, resembling a ladder twisted around itself. The DNA pol...

Deoxygenated blood enters at the vena cava. The right atrium receives the blood, and it then passes into the right ventricle. From there it goes to the lungs via the pulmonary artery. This brings the deox...

First of all, respiration is not breathing. Respiration is combining oxygen and glucose to form energy (ATP) with carbon dioxide as a waste product. All living things respire in order to obtain energy to ...

Atherosclerosis is the build up of fatty deposits within the arteries. This leads to a blockage of the artery, narrowing the lumen. If this happens to a coronary artery (one supplying the heart with blood...

Negative feedback is one of the ways the body maintains homeostasis. Homeostasis describes the body maintaining set internal conditions- for example the level of certain hormones in the body is kept in a ...