Prokaryotic vs Eukaryotic Cells — NEET Biology
📚 Practice ConceptAll organisms are made of cells or aggregates of cells. Cells vary in their shape, size and activities/functions, based on the presence or absence of a membrane bound nucleus and other organelles, cells and hence organisms can be named as eukaryotic or prokaryotic.
Which of the following statements correctly describe structures related to microtubules? S1: The mitotic spindle apparatus in animal cells is composed of microtubule-based structures that arise from centrioles. S2: Cilia and flagella both possess an axoneme core comprising nine radially arranged peripheral doublets of microtubules and a pair of centrally located microtubules. S3: Microfilaments are fine proteinaceous filaments forming a part of the cytoskeleton, distinct from microtubules, and are solely responsible for maintaining cell shape. S4: Centrosomes, which are non-membrane bound organelles, contain two centrioles arranged perpendicular to each other, both made of tubulin proteins. S5: Prokaryotic flagella, like eukaryotic flagella, exhibit a 9+2 arrangement of microtubules in their core.
View solution & NCERT explanation
Correct answer: B — S1, S2 and S4 are correct.
The core concept revolves around the composition and functions of microtubule-based structures in eukaryotic cells. S1: Correct. NCERT states that centrioles form 'spindle fibres that give rise to spindle apparatus during cell division in animal cells' and that centrioles are 'made up of nine evenly spaced peripheral fibrils of tubulin protein', thus the spindle fibres are microtubule-based. S2: Correct. NCERT states that the 'axoneme, possesses a number of microtubules running parallel to the long axis. The axoneme usually has nine doublets of radially arranged peripheral microtubules, and a pair of centrally located microtubules. Such an arrangement of axonemal microtubules is referred to as the 9+2 array.' S3: Incorrect. While microfilaments are distinct proteinaceous filaments part of the cytoskeleton, the cytoskeleton as a whole, comprising microtubules, microfilaments, and intermediate filaments, is involved in 'mechanical support, motility, maintenance of the shape of the cell', not microfilaments *solely* for cell shape. Also, their primary protein is actin, not tubulin. S4: Correct. NCERT states, 'Centrosome is an organelle usually containing two cylindrical structures called centrioles.' And 'Both the centrioles in a centrosome lie perpendicular to each other in which each has an organisation like the cartwheel. They are made up of nine evenly spaced peripheral fibrils of tubulin protein.' Centrosomes are non-membrane bound organelles mentioned in Section 8.3. S5: Incorrect. NCERT states, 'The prokaryotic bacteria also possess flagella but these are structurally different from that of the eukaryotic flagella.' Prokaryotic flagella lack the 9+2 microtubule arrangement. Therefore, statements S1, S2 and S4 are correct. The final answer is B.
What does NCERT say about All organisms are made?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.