The surface of the early Earth is often described as hellish by scientists. The high temperature is primarily attributed to the high levels of carbon dioxide in the atmosphere and the molten rock on the surface of the planet. However, these two aren't the only factors in play.
Another factor that contributed to the extremely high temperature of the early earth is radioactivity. Radioactive decay of the isotopes found underground plus the left over heat from the formation of our planet produced high levels of radiogenic heat.
There's also the kinetic energy from falling asteroids and meteorites. Massive amounts of energy in the form of heat and sound is produced when asteroids and meteorites hit the Earth. Also, the pressure waves that travel radially outwards the center of the impact is similar to the impact of an atom bomb. As such, dust particles envelop the atmosphere, trapping the heat from the impact.
The last factor is the gravitational contraction, it contributed to the hellish temperature of primordial Earth because the energy generated from such event is enough to trigger hydrogen fusion.
Answer ;
Phagocytosis is when smaller organisms or other food particles are eaten.
Autophagy is when a damaged organelle or small amount of cytosol becomes surrounded by a double membrane and a lysosome fuses with the outer membrane of the vesicle.
Enzymes break down the material. Food vacuoles fuse with a lysosome, whose enzymes digest the food.
Explanation;
-The Lysosomes are organelles that are responsible for intracellular digestion. Lysosomes are vesicles that contain hydrolytic digestive enzymes capable of breaking down large molecules into smaller ones.
-There are several ways in which different varieties of macromolecules may be digested by lysosomes. One mechanism is phagocytosis, the other is autophagy, which entails the removal of membrane-bounded organelles or other cytoplasmic components through the action of lysosomes, and lastly the hydrolytic enzymes may break down or digest the unwanted materials.
Answer:
a. Comparative molecular studies trace our earliest genetic material to Africa
Explanation:
With the development of the genetics we have been able to come to new findings or confirm some suspicions when it comes to the origin of the humans. The genetic analyses of the human DNA and the other hominids that have died out, as well as out closest ''cousins'' in the animal kingdom, have shown that the earliest human ancestors have evolved in Africa. Over time, as the conditions allowed it, the hominids started to migrate out of Africa and gradually started to settle all around the planet.
Answer:
B) cAMP
Explanation:
Phosphodiesterase is an enzyme that breaks a phosphodiester bond, for example in molecules such as cAMP and cGMP. So, phosphodiestarases are are regulators of signal transduction: regulate the duration of signaling pathway.
Caffeine is central-nervous-system stimulant and the mechanisms of its action usually are: mobilization of intracellular calcium or inhibition of specific phosphodiesterases.
1. One of the main reasons for the extinction of the trees in the Eastern Island is the extinction or sudden demise of the birds that carried the seeds to different places. Some of the human activities would have also led to the process of extinction, like the trees were being cut to construct canoes and to use as tools in order to erect statues, and to burn them for warmth.
2. There was a need to farm the trees and manage them in a proper framework. For example, if one is having 100 trees, then one should use 33 and then plant 33 seeds, and should always keep 34 intact. One should have not used all the trees at once.
