D. <span>They all contain carbon as an important part of their structure. Hope this helps you!! =')</span>
The correct answer is 4) A dichotomous key is complete when each organism stands alone.
The statement about a dichotomous key that is true is "A dichotomous key is complete when each organism stands alone."
Scientists have the need to correctly identify organisms, animals, plants, and objects. For that to happen, they have dichotomous keys.
These tools help them to identify and give a correct name that differentiates from other objects and organisms. So the most important thing about the dichotomous key is the fact that it identifies an organism, species or objects with its scientific name.
Answer:
amino acids
Explanation:
The building blocks of proteins are amino acids, which are small organic molecules that consist of an alpha (central) carbon atom linked to an amino group, a carboxyl group, a hydrogen atom, and a variable component called a side chain.
Hope this helps :)