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.

Option (a) Cells of all living organisms have a nucleus is incorrect

• Prokaryotic organisms lack a true nucleus and instead have genetic material in a nucleoid region

Option (b) Both animal and plant cells have a well defined cell wall is incorrect

• Only plant cells possess a rigid cell wall while animal cells are enclosed by a flexible plasma membrane

Option (c) In prokaryotes there are no membrane bound organelles is correct

• Prokaryotes lack organelles such as mitochondria chloroplasts and endoplasmic reticulum that are surrounded by membranes

Option (d) Cells are formed de novo from abiotic materials is incorrect

• Cell theory states all cells come from pre-existing cells under division disproving spontaneous generation