Cases of word usage

1) a very small kind of animal, consisting of one cell (amoeba)

2) a dark underground cell used (in history) as a prison (dungeon)

3) (plural ova) a cell in female animal, capable of developing into a new individual when fertilized (by male sperm) (ovum)

4) (a division of the animal kingdom consisting of) animals of the simplest type, formed of a single cell (protozoa)

5) a single cell by which a flowerless plant (e.g. moss, a fern) reproduces itself (spore)

6) a mass of cells and cell products in an animal body; (a piece of) thin, soft paper for wrapping things etc; a series (tissue)