Answer:
The answer is:
B. Worms consuming the blood from mammals.
Algae isn't causing any harm to the sloth, rather its providing it with camouflage to hide from predators. Both creatures benefits since the algae gets to eat any parasites and other things in the sloths fur, plus they get a free ride and home in the process. The sloth isn't harmed and is helped by the algae since it provides camouflage (mutualism).
Tree frogs aren't causing harm to the trees since they are only using them to hide from predators, the tree serves as protection for the frogs and aren't harmed in the process (commensalism).
Two fish protecting each other from predators aren't harming each other in any way, rather they are protecting each other from another animal that wants to eat them (mutualism).
The worms however are harming the mammals because they are consuming the mammals blood, this is parasitism since one animal is benefiting and the other is harmed.
Hope this helps! :)
Lead I believe would be the heaviest because gold is relatively light
The pancreas produces specific fat-friendly enzymes (e.g. pancreatic lipase) that helps to chemically break fats into smaller molecules (fatty acids and glycerol), which are then in a more suitable form to be absorbed in the small intestine.
