1. What is the primary function of ribosomes in a cell?
A) To synthesize lipids
B) To produce ATP
C) To synthesize proteins
D) To store genetic information
Answer: C) To synthesize proteins
2. Ribosomes are composed of which two major components?
A) DNA and RNA
B) mRNA and tRNA
C) Protein and rRNA
D) mRNA and ribosomal proteins
Answer: C) Protein and rRNA
3. Ribosomes are found in which parts of the cell?
A) Nucleus and cytoplasm
B) Cytoplasm and rough endoplasmic reticulum
C) Mitochondria and nucleus
D) Golgi apparatus and cytoplasm
Answer: B) Cytoplasm and rough endoplasmic reticulum
4. During translation, ribosomes bind to which type of RNA?
A) mRNA
B) rRNA
C) tRNA
D) hnRNA
Answer: A) mRNA
5. The small subunit of a ribosome is responsible for: A) Carrying amino acids
B) Binding to mRNA
C) Catalyzing peptide bonds
D) Synthesizing proteins
Answer: B) Binding to mRNA
6. What is the function of the large subunit of the ribosome?
A) To bind tRNA
B) To catalyze protein synthesis
C) To carry amino acids
D) To interact with DNA
Answer: B) To catalyze protein synthesis
7. Ribosomes can be found in which of the following?
A) Both prokaryotes and eukaryotes
B) Only prokaryotes
C) Only eukaryotes
D) Only in mitochondria
Answer: A) Both prokaryotes and eukaryotes
8. What is the name of the process in which ribosomes help synthesize proteins?
A) Replication
B) Transcription
C) Translation
D) Transposition
Answer: C) Translation
9. What type of RNA carries amino acids to the ribosome during translation?
A) mRNA
B) rRNA
C) tRNA
D) hnRNA
Answer: C) tRNA
10. Which of the following is NOT a function of ribosomes?
A) Translating genetic information into proteins
B) Reading codons from mRNA
C) Synthesizing tRNA
D) Forming peptide bonds between amino acids
Answer: C) Synthesizing tRNA
11. The “A” site of a ribosome is responsible for: A) Holding the tRNA that carries the growing polypeptide chain
B) Attaching to the mRNA molecule
C) Binding to the tRNA with the next amino acid
D) Catalyzing the peptide bond formation
Answer: C) Binding to the tRNA with the next amino acid
12. In protein synthesis, the ribosome moves along the mRNA in which direction?
A) 5′ to 3′
B) 3′ to 5′
C) 3′ to 3′
D) 5′ to 5′
Answer: A) 5′ to 3′
13. The ribosome is primarily made up of which two molecules?
A) mRNA and rRNA
B) tRNA and mRNA
C) rRNA and protein
D) Protein and lipids
Answer: C) rRNA and protein
14. What happens at the “P” site of the ribosome during translation?
A) tRNA carrying the polypeptide chain binds
B) Amino acids are added to the chain
C) The ribosome attaches to mRNA
D) tRNA binds to the next codon
Answer: A) tRNA carrying the polypeptide chain binds
15. In prokaryotes, ribosomes are composed of how many subunits?
A) One large subunit
B) Two subunits
C) Three subunits
D) Four subunits
Answer: B) Two subunits
16. In eukaryotes, the ribosome is composed of which subunits?
A) 40S and 60S
B) 50S and 60S
C) 70S and 80S
D) 80S and 90S
Answer: A) 40S and 60S
17. Ribosome binding to mRNA starts at which sequence?
A) Shine-Dalgarno sequence
B) AUG codon
C) Promoter sequence
D) Terminator sequence
Answer: B) AUG codon
18. Which of the following best describes the role of ribosomes in cellular functions?
A) Synthesizing RNA molecules
B) Synthesizing lipids and carbohydrates
C) Translating genetic information into proteins
D) Breaking down cellular waste
Answer: C) Translating genetic information into proteins
19. What is the function of the E site on the ribosome?
A) It is the site for peptide bond formation.
B) It is where tRNA exits the ribosome.
C) It binds to the mRNA.
D) It is where amino acids are added to the chain.
Answer: B) It is where tRNA exits the ribosome.
20. What is the role of rRNA in the ribosome?
A) Carrying amino acids
B) Catalyzing the formation of peptide bonds
C) Storing genetic information
D) Providing a template for protein synthesis
Answer: B) Catalyzing the formation of peptide bonds
21. Ribosomes are crucial for the synthesis of proteins. What is the first step in protein synthesis?
A) Elongation
B) Transcription
C) Initiation
D) Termination
Answer: C) Initiation
22. Which enzyme catalyzes the formation of peptide bonds between amino acids in the ribosome?
A) RNA polymerase
B) Peptidyl transferase
C) DNA polymerase
D) Aminoacyl tRNA synthetase
Answer: B) Peptidyl transferase
23. Which type of RNA is primarily involved in the structure of ribosomes?
A) mRNA
B) rRNA
C) tRNA
D) siRNA
Answer: B) rRNA
24. What does the mRNA codon sequence determine during translation?
A) The amino acid sequence in a protein
B) The folding of the protein
C) The energy required for protein synthesis
D) The location of ribosomes in the cytoplasm
Answer: A) The amino acid sequence in a protein
25. What is the main consequence of a ribosomal malfunction in a cell?
A) Increased protein synthesis
B) Decreased protein synthesis
C) Mutations in the DNA sequence
D) Accelerated cell division
Answer: B) Decreased protein synthesis
26. Which step of translation requires energy in the form of GTP?
A) Initiation
B) Elongation
C) Termination
D) All of the above
Answer: D) All of the above
27. In translation, the ribosome reads the mRNA in groups of how many nucleotides?
A) 1
B) 2
C) 3
D) 4
Answer: C) 3
28. The process by which ribosomes synthesize proteins is known as: A) Replication
B) Transcription
C) Translation
D) Replication
Answer: C) Translation
29. What is the role of the anticodon in translation?
A) It carries the amino acid to the ribosome.
B) It binds to the corresponding codon on the mRNA.
C) It initiates the synthesis of mRNA.
D) It catalyzes the formation of peptide bonds.
Answer: B) It binds to the corresponding codon on the mRNA.
30. What happens when the ribosome reaches a stop codon during translation?
A) The ribosome continues translating
B) The polypeptide is released
C) The tRNA binds to the stop codon
D) The mRNA is degraded
Answer: B) The polypeptide is released
These MCQs cover various aspects of ribosome function in protein synthesis, from structure to the molecular processes involved in translation.
