The answer is C. nitrogen.
Plants are main producers in ecosystems so, primary productivity of ecosystems depends on them. Carbon is necessary for plants, but it is widely present in plants. On the other hand, calcium and sodium are not as essential. However, nitrogen is important for plants because it is necessary to make proteins. Proteins take part in many different processes such as photosynthesis (this is actually primary productivity). But, nitrogen is not available to plants, they cannot absorb it simply from the air but rely on some symbiotic bacteria which are able to.
Answer:
cellular respiration breaks down sugars and other molecules to use the stored energy
Answer:
When petting a dog, mechanoreceptors in the skin of your hand send signals to the sensory neuron. The sensory neuron connects to your spinal cord and through your brain.
Explanation:
Answer:
The features that are found in both cartilage and bone are, living cells embedded in a matrix
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