All planets have these same layers (From deepest to shallowest, inner core then the outer core, then the mantle, and lastly the crust. A good example is the Earth) that is shown in the diagram, even the sun has all the layers I just listed.
But, some planets I can think of are Mars, Venus, Moon, and the Earth of course.
Layer C. sounds like it could also represent Layer D, since they are so close.
P. S. I did my best to try to answer this.
Answer:
The nitrogen cycle could not exist without the presence of nitrogen-fixing microorganisms.
Explanation:
As part of the biogeochemical cycles that occur in nature, the nitrogen cycle involves all the organic and non-organic processes that allow the incorporation of this element into the organism of living beings.
Although nitrogen is abundant in nature, in gaseous form, living beings cannot take advantage of it, because they lack the ability to convert this gas into organic nitrogen. Nitrogen-fixing microorganisms -such as bacteria in the soil- turn inorganic nitrogen into organic, that incorporates plants.
Nitrogen-fixing bacteria exist in both soil and plant roots. They are responsible for the conversion of atmospheric nitrogen and ammonium, the product of the degradation of organic matter, into nitrites and nitrates that assimilate the plants. Herbivorous animals obtain this nitrogen from vegetables, and carnivores from them.
Learn more:
brainly.com/question/4935397
I'm pretty sure the answer is: B. Sickle-cell disease
