What charteristics are common to all to all plants and animals

Flock x flock y flock z total pieces of food eaten (from previous page) 147 93 60 food percentage* % % % simulated number of birds in flock for 3rd generation** * divide each flock's total pieces of food by 300, the total number of pieces of food eaten. ** multiply the food percentage for each flock by the total number of birds (30).

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks

What substance acts to prevent sudden ph changes in bodily fluids?