within animal cells, what is the function of the cell membrane? What is it comprised of?
The cell membrane provides structure to the cell and allows for the diffusion and transportation of molecules to and from the cell. The cell membrane is comprised of a phospholipid bilayer in which each phospholipid "head" is hydrophilic and each "tail" is hydrophobic. Amongst the phospholipids are several different proteins which function in the transport of molecules across the cell membrane.
What is the process of eutrophication? give a relavent real-world example.
Eutrophication is the process in which an excess of nutrients is leached into water systems. This excess of nutrients can often lead to algal blooms and thus deprive a water body of its oxygen. A real-world example of this would be the Mississippi River causing eutrophication within the gulf of Mexico. Due to the use of fertilizers within agricultural activity along the Mississippi river nutrients from these fertilizers often leach into the river through farm soils and thus flow into the gulf of Mexico.
What is unique about the circulatory system of cephalopods compared to other mollusks and why is it evolutionarily benificial?
Cephalopods have closed circulatory systems compared to the open systems characteristic the other classes within the phylum molluska. This is evolutionarily beneficial to cephalopods as due to their predatory nature. The closed circulatory system allows for quicker and more efficient blood circulation throughout the body. This then helps to supply the high oxygen demand caused by the animal's active lifestyle.