Answer :
Answer:
a cell
Explanation:
all living things start off as a single cell
answer: cell
explanation: cells are the “building block of life”. all life is made of cells, then groups of cells make tissues, groups of tissues make organs, and organs make organ systems and so forth.
explanation: cells are the “building block of life”. all life is made of cells, then groups of cells make tissues, groups of tissues make organs, and organs make organ systems and so forth.