Answer and Explanation:
During the whole biota history, there occurred extinctions due to different reasons.
During the Cretaceous, which took place between 145-65 million years ago, there occurred a massive extinction that eliminated most of the species on the Earth. Many of the characteristic groups of this period were affected. Dinosaurs, Plesiosaurs, Ammonites, Tricodonts, Cycas, Gynkgos, Conifers, the recent angiosperms, birds, and mammals.
The extinction was caused by the volcanic eruptions, and the unusual fall of many different asteroids, which caused important changes on the Earth´s surface. The consequent climatic change was what ended affecting all the species directly. The extinction was gradual, although it occurred in a short geological lapse of time.
A simple columnar epithelium<span> is a </span>columnar epithelium<span> that is uni-layered. In humans, a simple </span>columnar epithelium<span> lines most </span>organs<span> of the digestive tract including the stomach, small intestine, and large intestine. Simple columnar epithelia line the </span>uterus<span>.</span>
It stores the cell's hereditary material, or DNA, and it coordinates the cell's activities, which include intermediary metabolism, growth, protein synthesis, and reproduction (cell division). The diverse functions of the ER are performed by distinct domains; consisting of tubules, sheets and the nuclear envelope.
Answer:
the pain he feels when he is hungry
Explanation:
Black Boy is a memoir that was written by the author Richard Wright in which he describes in detail what it was like for him growing up in the South as well as moving to Chicago in order to start his career. In this memoir he associates the bitterness and pain he feels over being abandoned by his father with the pain he feels when he is hungry
The rapid depolarization phase of the action potentials of myocardial contractile cells is due to Na⁺ ion.
The depolarization is caused when Na⁺ ions rapidly enters into neuron through open sodium channels. Sodium ions plays important role in various physiological process such as regulating blood volume, ph regulation, maintaining blood pressure, energy metabolism,osmotic equilibrium, excitation-contraction coupling, maintenance of cellular homeostasis, development and growth.
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