Ruminant herbivores gain from the microflora in their gut through digestion of cellulose and in return, the microflora gets the nutrients from the ruminants. The shark doesn't benefit from the remora but the remora gets a free ride from the shark and it feeds on the leftovers from the shark's meal. The human host loses nutrients because the tapeworm gets to eat the food provided by the host. Cats provide shelter and food for the flea but the cat becomes anemic because of blood loss from its parasites.
I don't have an answer, but your doing this in college, when I need this in my 6th grade earth science? dang lol
Explanation:
It should be in this order from oldest to youngest: 2,1,5,7,9,3,4,8,6.
Since we know 2 is the oldest and once each organism goes extinct it stops being in any samples, we can start at 2 and go through the samples to see where that fossil shows up again and when we find the next sample its in, we pay attention to any new fossils that show up and move onto the next sample with the second fossil in it and so on.
Genetics, nutrition, fitness, sleep etc.