When blood pH decreases, the urinary system helps to maintain the extracellular fluid pH by 01.
excreting excess hydrogen ions and reabsorbing bicarbonates
2. synthesizing buffers
03
retaining carbon dioxide in the filtrate
4. excreting filtrate

primary succession begins with a bare rock and ends with a forest secondary succession begins after a natural disaster where there is a temporary setback after a forest fire or local destruction, but the surrounding area can fill in

as in mitosis, dna replication occurs during interphase.   in meiosis, it occurs specifically in s phase of interphase 1.

d. organisms have cells with different shapes and functions.