Question

Which is correct option amongst the following statements?

a. Nuclear membrane, chloroplasts, mitochondria, microtubules and pili are absent in prokaryotic cells.

b.Nuclear membrane, chloroplasts, mitochondria, microtubules and pili are present in prokaryotic cells.

c. Ribosomes are $70S$ in prokaryotic cells, chloroplasts and mitochondria. They are $80S$ in animal cells.

• A. a and b are wrong, c is correct
• B. a and c are correct, b is wrong
• C. a and b are correct, c is wrong
• D. a is correct, b and c are wrong

Answer 1

The correct option is A a and b are wrong, c is correct

Statement a

Statement : Nuclear membrane, chloroplasts, mitochondria, microtubules and pili are absent in prokaryotic cells.

Elaboration : Nuclear membrane, chloroplasts and mitochondria are found in eukaryotic cells but absent in prokaryotic cells. Microtubules are present in both prokaryotic and eukaryotic cells. Pili are extensions of cell membranes in prokaryotes. Hence, statement (a) is incorrect.

Statement b

Statement : Nuclear membrane, chloroplasts, mitochondria, microtubules and pili are present in prokaryotic cells.

Elaboration : Nuclear membrane, chloroplasts, mitochondria are present only in eukaryotic cells. Microtubules are protein structures found in both prokaryotic and eukaryotic cell. Pili are cell membrane extensions found only in prokaryotes. Hence, statement (b) is incorrect.

Statement c

Statement : Ribosomes are $70S$ in prokaryotic cells, chloroplasts and mitochondria. They are $80S$ in animal cells.

Elaboration : Ribosomes are membraneless organelles found in both prokaryotes and eukaryotes. $70S$ types of ribosomes are found in prokaryotes and organelles like mitochondria and chloroplast. $80S$ types of ribosomes are found in eukaryotes like animal cells. Hence, statement (c) is correct.

Final answer

(A) a and b are wrong, c is correct