I'm not completely sure about this answer because our unit on that was very short. So please don't be upset if its incorrect.
The answer is phytoplankton and water depth, because in order for any ecosystem to survive they need the producer population (Plants)
Middle School
Basic Rank
A virus<span> is a small </span>infectious agent<span> that </span>replicates<span> only inside the living </span>cells<span> of other </span>organisms<span>. Viruses can infect all types of </span>life forms<span>, from </span>animals<span> and </span>plants<span> to </span>microorganisms<span>, including </span>bacteria<span> and </span><span>archaea
</span>While not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles. These viral particles<span>, also known as </span>virions<span>, consist of two or three parts: (i) the </span>genetic material<span> made from either </span>DNA<span> or </span>RNA<span>, long </span>molecules<span> that carry genetic information; (ii) a </span>protein<span> coat, called the </span>capsid<span>, which surrounds and protects the genetic material; and in some cases (iii) an </span>envelope<span> of </span>lipids<span> that surrounds the protein coat when they are outside a cell. The shapes of these virus particles range from simple </span>helical<span> and </span>icosahedral<span> forms for some virus species to more complex structures for others. Most virus species have virions that are too small to be seen with an </span>optical microscope<span>. The average virion is about one one-hundredth the size of the average </span>bacterium<span>.</span>
Gravitational push<span>, like a gigantic landslide away from the </span>ridge<span> crest toward the subduction zone (the lithosphere slides on the asthensosphere) </span>Slab pull<span>: results when the lithospheric plate moves farther from the </span>ridge<span> and cools, gradually becoming denser than the asthenosphere beneath it
Hope this helps. :)</span>
In photosynthesis, a thylakoid is a sac located in a chloroplast which absorbs light in the form of photons through proteins called Photosystems I and II and cytochrome complexes and uses it to harvest ATP. All of this occurs during the light reaction step of photosynthesis on the membranes of the thylakoids.