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In Spanish we form a verbal periphrasis to express a single idea by using two verbs in the same sentence, in a similar way in English we use Phrasal verbs. Their usual structure is: Auxiliary verb + nexus (might not be present) + verb (impersonal form). The different types of verbal periphrasis are:
Tienes que concentrarte en tus deberes (You must concentrate on your homework)
Iba a salir ahora (I was about to leave now)
No volveré a ir allí (I won’t go there any more)see more
Lynn Margulis proposed this theory in 1996. It explains how the eukaryotic cells engulfed through endophagocytosis some organelles such as mitochondria and chloroplasts, which evolved from bacteria. The cell and the mitochondria/chloroplast entered then in a endosymbiotic relationship: by one side, the new organelle (the bacterium) provided the cell with energy, while the cell acted as a host for the bacterium.
According to this theory, probably the cell was initially anaerobic, while the bacterium was aerobic. The cell failed in digesting the bacterium, which lived inside the cell, producing energy that the cell could use and allowing it to breath aerobically. Eventually the bacterium could not live independently, becoming a cell organelle.see more
Every cell of our body has two different kind of DNA: nuclear and mitochondrial. The nuclear DNA is found in the nucleus of the cell, and is inherited from both parents. However, the mitochondrial DNA, which is inside the mitochondria, is inherited only from the mother. This is because when the spermatozoon fertilizes the ovum, it loses its tail, and only the nucleus of the cell is present, while the ovum preserves its organelles, such as mitochondria. So every mitochondria in our body is inherited from our mothers, who inherited from their mothers, and so on and so forth. When a woman doesn’t have daughters, her mitochondrial DNA is not transmitted, and her line is considered broken.
The name Mitochondrial Eve refers to the matrilineal most recent common ancestor, in an unbroken maternal line, of all currently living humans, who is estimated to have lived approximately 100,000–200,000 years ago. This doesn’t mean this woman (Mitochondrial Eve) was ‘the mother’ of all living humans today, or that she was 'the first woman'. It means that, in an unbroken line, she is the most recent woman from whom all living humans today descend.see more