Answer:
Newer layers of earth form <u>on</u><u> </u><u>top</u> of older layers, so as we dig, we can see further back in time. Comparing the fossils between the layers can offer evidence of change.
<u>Phyletic</u><u> </u><u>gradualism</u> - slow, but constant gradual change; supported by transitional species in the fossil record
<u>Punctuated</u><u> </u><u>equilibrium</u>- long periods of no change followed by short periods of rapid change. Can also be supported by the fossil record when no transitional species are found.
Mark the pink dot with “phosphate group”
mark the blue one with “nitrogen bases”
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.