The right answer is C.
Classically positive interactions or facilitators between species are divided into two broad categories:
- those where the two partners involved benefit from each other: the mutualisms (symbolized by + / +)
- those where one of the two partners makes a profit or an advantage while the other gets nothing from it without being affected negatively: it is the commensalism symbolized by + / 0.
It may be that bacterial commensalism has an interest in its host (the animal) in the sense that it protects against parasites, or on the contrary, it favors their appearance.
Biodiversity is essential to an ecosystem's resistance against viruses and famine. In history, there has been many cases in which a lack of biodiversity has allowed a virus or disease to endemically wipe out an entire species of plant. This will subsequently affect all consumers of each trophic level. Ex: A disease that attacks the DNA of only one certain species of plant would cause decreases in the population of the organisms that rely on eating that plant, the organisms that rely on eating those organisms, and so on. This is caused by a decrease in food source, thus not being able to sustain the ecosystem's demand, thus naturally killing off any organisms that would not be able to find a sufficient food source.
Tight hydrogen bonding
The atoms in a compound are held together by a chemical bond. The chemical bonds can be either covalent bonds or ionic bonds. Both the bonds are considered very strong bonds. These bonds are mainly formed by sharing of electrons or in the case when one of the elements making the compound donates electron to the other element. The nucleus of each atom attracts to form a strong bond. This property of attraction between the nucleus of the atoms actually helps in forming the chemical bonds.<span>
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