Which sentence describes existing cells?

a.

all cells come from previously existing cells.

b.
all cells develop from the remains of other cells.

c.
all cells, once formed, continue to live forever.

d.

all the cells that are on earth have always been here.

The correct answer is option A. All cells come from previously existing cells.

Explanation:

According to the cell theory presented Schleiden and Schwann. The cell theory is universally accepted now. It has 3 major points that are all organisms are made up of structural and functional unit cell.

They can be multi cellular or unicellular. Cell come from the cells that are already present.

Thus, the correct answer is option A. All cells come from previously existing cells.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

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