Hydrogen bonds are classified as weak because they are formed fast, but they also break easily under normal biological conditions.
Weak bonds can be easily broken, but this is extremely important because they are in bold in biological systems. For example, they help to decide and stabilize the shapes of water molecules.
C. one celled
because like animals they can move and are hetrotrauphs
The answer is D. A species diversity
The ear cavity (which is affected in infectious otitis) is connected by a duct (the Eustachian tube) to the nasopharynx located behind the nasal fossae.
Otitis is related to a bacterial or viral infection, which most often contaminating the middle ear as a result of rhino-sinusitis or rhino-pharyngitis by borrowing the Eustachian tube or vice versa (otitis media evolving towards a pharyngitis).
The answer to this easy specific question is DNA and you are welcome for the help.