<span>The answer is cysteine. This is a half essential proteinogenic amino acid with the formulation of HO₂CCHCH₂SH. It is prearranged by the codons UGU and UGC. The thiol side chain in cysteine frequently partakes in enzymatic responses, as a nucleophile.</span>
When animals are fighting over resources the number of one animal might decrease because the other animal would've tried to kill it and stay alive
when there is competition the population size of one animal might decrease while another increases<span />
If I'm not mistaken, it leaves through the osculum which is a cavity located on the upper part of a sponge.
Sponges feed through a process called filtration, which means that they filter the water in search of nutrients. And after they collect everything they need from the water, they need to let it out somehow; through the osculum.
Hope it helped,
BioTeacher101