Why should we think that a mitochondrion used to be a free-living organism ... Based on decades of accumulated evidence, the scientific community ... The evidence suggests that these chloroplast organelles were also once free-living bacteria. ... to be the irreversible step at which the two independent organisms
When the heart contracts, called systole, blood pressure increases. When the heart relaxes, called diastole, blood pressure decreases. Systole phase or contraction is started by the electrical cells of the sinoatrial node. The diastole phase is the period when the heart relaxes after contraction.<span> </span>
Ok jfndkkdkdkckd thanks for the points lol