A model organism is a species that has been widely studied to understand a particular biological phenomena, normally used because they are easy to breed and maintain in a laboratory setting and has certain experimental advantage.
The criteria that Thomas hunt Morgan was looking for include; the model organism should be small in size, easy to keep in the laboratory and also able to produce large number of off springs in a short time.
<span>A vesícula biliar é uma estrutura em forma de pêra, oca localizada sob o fígado e no lado direito do abdômen. Sua principal função é armazenar e concentrar a bile, uma enzima digestiva marrom-amarela produzida pelo fígado. A vesícula biliar é parte do trato biliar.</span>
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:
I don't know sorry
Explanation:
I thought I new the answer but now I am not sure.