Answer:
Fossil records provide evidence of an increase in animal species at the same time that atmospheric oxygen levels increased.
Explanation:
A huge diversification among animal species occurred with the increase in the levels of atmospheric oxygen. The reason why the number of species increased drastically was that a whole new world opened up, the land. The land was open for exploitation and taking over, with every single niche free, so animals diversified and filled in pretty much all of the niches. The fossil records give us clues when this happened, as from only microorganisms there is a sharp rise in complex animals, coinciding with the increase of oxygen levels.
If it wasn't for the increase of atmospheric oxygen though this wouldn't have been possible. The oxygen in the atmosphere enabled animals to breathe on land. Also, it cooled off the global temperatures which were too high before the increase of atmospheric oxygen, making them suitable for life. And last but not least, the atmospheric oxygen resulted in the formation of the ozone layer, a layer that started to act as protection from the UV rays.
Answer:
H2O
Explanation:
Water molecule is made of 2 hydrogen atoms bonded with covalent union (sharing electrons) with 1 oxigen molecule
Answer: Vena cava also know as (SVC).
Explanation: Blood provides oxygen and nutrients to the body and removes carbon dioxide and wastes. Oxygen-poor blood returns from the body to the heart through the superior vena cava also know as (SVC) and also inferior vena cava (IVC), these are the two main veins that bring blood back to the heart.
For example, in a polarized epithelial cell, the apical surface is the exposed surface and lies opposite to the basal lamina that separates the epithelium from other tissue.
