Question

which is the most prominent structure observed in cells of onion peel plants

Answer 1

Nucleus is the most prominent structure observed in cells of onion peel plants

Answer 2

" Nucleus "

Most prominently observed structure observed in cells of onion peels under the slide is nucleus.

After staining of onion peel with saffrain solution mostly the nucleus turns into deal color indicating its identity.

While you can also observe thin cell walls as well as small little gaps between two cells.