Which of the following is correct:
(a) Cells of all living organisms have a nucleus.
(b) Both animal and plant cells have a well defined cell wall.
(c) In prokaryotes, there are no membrane bound organelles.
(d) Cells are formed de novo from abiotic materials.

(c) Membrane-bound organelles are organelles surrounded by a double or a single membrane like Nucleus, mitochondria, chloroplasts, Lysosomes, ER, Golgi bodies etc. are examples of such organelles. These cell organelles are absent in prokaryotes.

(a) Only eukaryotic cells have nuclei. They are absent in prokaryotes.

(b) Cell walls are only present in plant cells. They are absent in all animal cells.

(d) All cells arise from pre-existing cells.