The word phase means to change a part of a development
Parenchyma is the answer because whereas the other two, xylem and phloem are vascular tissues, parenchyma is a packing tissue.
That organelle is the mitochondria
The names of most enzymes end in "-ase." Some enzymes which have been known longer have older names that don't end in "ase." For example: pepsin, trypsin, and chrymotrypsin which are all enzymes localized in the digestive tract. hope u got the point