Answer:
One difference between the Rhesus system and the ABO group system is that Rh negative people don't usually possess antibodies against RhD (unless they have been previously exposed to it), whereas in the ABO group system if the antigen is absent from the red blood cells.
Here is the link to read more :)
https://www.mydr.com.au/tests-investigations/blood-typing
Each level of the food chain is a trophic level. hope this helps and i'm not too late!
The diaphragm, next time just google it lol