Question
What is the primary function of the free ribosomes shown in the electron micrograph?
A. Synthesize proteins to be used within the cell
B. Synthesize proteins for use in lysosomes
C. Carry amino acids to mRNA for protein synthesis
D. Synthesize proteins for secretion
▶️Answer/Explanation
Ans:A
Question
Which types of interactions are found in a part of a protein with secondary but not tertiary structure?
I. Hydrogen bonds
II. Disulphide bridges
III. Ionic bonds
A. I only
B. I and II only
C. II and III only
D. I, II and III
▶️Answer/Explanation
Ans:A
Question
This DNA sequence was used to synthesize a polypeptide.
DNA (sense strand): 3′ T A C T G A 5′
DNA (template strand): 5′ A T G A C T 3′
Which are the bases of the tRNA (anticodons)?
A. T A C T G A
B. U A C U G A
C. A U G A C U
D. A T G A C T
▶️Answer/Explanation
Ans:C
Question
A DNA triplet on the strand that is transcribed has the bases TAG. Which anticodon on tRNA is used in translation?
A. AUC
B. UAG
C. TAG
D. ATC
▶️Answer/Explanation
B
Question
What is a feature of transcription in the single-celled organism shown in the electron micrograph?
A. mRNA splicing
B. Removal of introns
C. Codon-anticodon binding
D. Synthesis of RNA in a 5′ to 3′ direction
▶️Answer/Explanation
D
Question
The anticodons of three tRNAs and the amino acids they carry are shown in the table.
Which base sequence of an mRNA molecule would code for an arginine–leucine–valine tripeptide?
A. GCA AAU CAG
B. GCA AAT CAG
C. CGT TTA GTC
D. CGU UUA GUC
▶️Answer/Explanation
D