Answer:
You can't see the blood vessels themselves because vision depends on a process that makes it impossible to see things that are stationary with respect to the retina. Light receptors in the retina respond only to changes in light reaching them, not to a steady image.
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Answer:
the rhythm of heart contractions.
Explanation:
In Human anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.
Generally, the cardiac cycle occurs in two (2) stages;
1. Diastole : in this stage, the ventricles is relaxed and would be filled with blood.
2. Systole: at this stage, the muscles contracts and thus, allow blood to be pushed through the atria.
An electrocardiogram (ECG) provides information about the rhythm of heart contractions.
Additionally, the right atrioventricular valve (AV) also referred to as the tricuspid valve is located on the right dorsal side of the human heart. The right atrioventricular valve (AV) comprises of three (3) leaflets (flaps) which opens and closes in order to allow for the flow of blood from the right atrium of the human heart to the right ventricle. Also, the right atrioventricular valve is saddled with the responsibility of preventing blood from flowing backward in the mammalian heart.
Asexual reproduction produces offspring with identical DNA to the parent and sexual offspring has a combination of DNA from two parents.
When the cells undergo late apoptosis, the membrane structure is destroyed and the nuclear structure can be selectively visualized by Hoechst 33342/PI.
https://www.creative-bioarray.com/support/double-staining-apoptosis-assay-hoechst33342-pi.htm