Ribosomes and the Cytoskeleton Practice Questions
20 free Ribosomes and the Cytoskeleton practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
What is the primary function of ribosomes in a cell?
- A Lipid synthesis
- B Protein synthesis
- C DNA replication
- D Energy production
Correct answer: Protein synthesis
Ribosomes are the sites of protein synthesis. They translate mRNA into polypeptide chains.
Ribosomes are composed of:
- A DNA and protein
- B RNA and protein
- C Lipids and protein
- D Carbohydrates and RNA
Correct answer: RNA and protein
Ribosomes consist of ribosomal RNA (rRNA) and proteins. These components form large and small subunits.
Which type of ribosomes are found in prokaryotic cells?
- A 80S
- B 70S
- C 60S
- D 90S
Correct answer: 70S
Prokaryotic cells have 70S ribosomes. They are smaller than the 80S ribosomes of eukaryotes.
Which type of ribosomes are found in eukaryotic cytoplasm?
- A 70S
- B 50S
- C 30S
- D 80S
Correct answer: 80S
Eukaryotic cells have 80S ribosomes in the cytoplasm. They consist of 60S and 40S subunits.
Which structure forms the cytoskeleton in cells?
- A Ribosomes
- B Golgi apparatus and lysosomal enzymes
- C Lysosomes
- D Microtubules and microfilaments
Correct answer: Microtubules and microfilaments
The cytoskeleton is made up of microtubules, microfilaments, and intermediate filaments. It provides structural support.
Microtubules are primarily composed of which protein?
- A Actin
- B Myosin
- C Collagen
- D Tubulin
Correct answer: Tubulin
Microtubules are made of tubulin protein subunits. They form hollow cylindrical structures.
Microfilaments are mainly composed of:
- A Tubulin
- B Keratin
- C Titin
- D Actin
Correct answer: Actin
Microfilaments are made of actin protein. They are thin filaments involved in cell movement.
Which cytoskeletal component is involved in maintaining cell shape?
- A Ribosomes
- B Microtubules
- C Microfilaments
- D All of the above
Correct answer: Microtubules
Microtubules are the principal cytoskeletal component that resists compression and maintains overall cell shape; microfilaments contribute mainly to the cell cortex and surface changes, while ribosomes are protein-synthesis machinery with no structural role.
Which structure is responsible for chromosome movement during cell division?
- A Microfilaments
- B Ribosomes
- C Golgi apparatus
- D Microtubules
Correct answer: Microtubules
Microtubules form the spindle fibers. These fibers help in the movement of chromosomes during mitosis.
Which type of ribosomes are attached to the rough endoplasmic reticulum?
- A Unattached ribosomes
- B 70S ribosomes
- C 30S ribosomes
- D Bound ribosomes
Correct answer: Bound ribosomes
Bound ribosomes are attached to the rough ER. They synthesize proteins destined for secretion or membranes.
Which type of ribosomes occur dispersed in the cytoplasm, not attached to any membrane?
- A Bound ribosomes
- B Plastid ribosomes
- C Free ribosomes
- D 70S ribosomes
Correct answer: Free ribosomes
Free ribosomes float in the cytoplasm. They synthesize proteins used within the cell.
Which cytoskeletal component is involved in cell motility and contraction?
- A Microtubules
- B Ribosomes
- C Microfilaments
- D Intermediate filaments
Correct answer: Microfilaments
Microfilaments, made of actin, are involved in muscle contraction and cell movement. They play a key role in motility.
Which structure is formed by microtubules and is involved in locomotion?
- A Cilia and flagella
- B Ribosomal complexes
- C Nucleus
- D Golgi apparatus
Correct answer: Cilia and flagella
Microtubules form structures like cilia and flagella. These help in cell movement.
Which arrangement of microtubules is found in cilia and flagella?
- A 9+2 arrangement
- B 8+2 arrangement
- C 10+2 arrangement
- D 7+2 arrangement
Correct answer: 9+2 arrangement
Cilia and flagella have a 9+2 arrangement of microtubules. This structure enables movement.
Which structure organizes microtubules in animal cells?
- A Centrosome
- B Nucleus
- C Golgi apparatus
- D Lysosome
Correct answer: Centrosome
The centrosome acts as a microtubule organizing center. It plays a role in cell division.
Which cytoskeletal component provides tensile strength to the cell?
- A Microtubules
- B Microfilaments
- C Intermediate filaments
- D Golgi transport vesicles
Correct answer: Intermediate filaments
Intermediate filaments provide tensile strength. They help cells withstand mechanical stress.
Which type of protein synthesis occurs on free ribosomes?
- A Secretory proteins
- B Membrane proteins
- C Cytosolic proteins
- D Lysosomal enzymes
Correct answer: Cytosolic proteins
Free ribosomes synthesize proteins that function within the cytosol. They are not transported outside the cell.
Which cytoskeletal element is hollow and tubular?
- A Microtubule
- B Microfilament
- C Intermediate filament
- D Ribosome
Correct answer: Microtubule
Microtubules are hollow tubes made of tubulin. They help in intracellular transport and cell division.
Which of the following is NOT a function of the cytoskeleton?
- A Maintaining cell shape
- B Intracellular transport
- C Protein synthesis
- D Cell movement
Correct answer: Protein synthesis
Protein synthesis is carried out by ribosomes. The cytoskeleton mainly provides structure and transport.
Which structure helps in the movement of vesicles within the cell?
- A Microtubules
- B Ribosomes
- C Nucleus
- D Chloroplasts
Correct answer: Microtubules
Microtubules act as tracks for vesicle transport. Motor proteins move vesicles along them.