Sunlight
solar energy
water
Biome, though some might say ecosystem instead. Biomes are very large ecosystems that cover broad areas.<span>If they specify "one" reef, then they are probably looking for "ecosystem"</span>
<span>The major difference between viruses and living cells is that viruses do not have nuclei while living cells do. A second major difference is that viruses need a host cell to survive while living cells do not. For the most part, viruses just contain genetic material (typically in the form of RNA) inside of a capsid. Living cells have many more organelles, including ribosomes and cytoplasm, which viruses lack.</span>
<span>Living things respond to stimuli in the environment.</span>
