Biology Test Biology Microbiology and Biotechnology 2 — Questions and Answers
Question 1: Which type of RNA carries amino acids to the ribosome during translation?
- mRNA
- rRNA
- tRNA (Correct answer)
- snRNA
Correct answer: tRNA
Transfer RNA (tRNA) carries specific amino acids to the ribosome, matching anticodons to mRNA codons.
Question 2: What is the function of restriction endonucleases in biotechnology?
- Join DNA fragments together
- Replicate DNA strands
- Cut DNA at specific sequences (Correct answer)
- Transcribe DNA into RNA
Correct answer: Cut DNA at specific sequences
Restriction endonucleases recognize and cut DNA at specific palindromic sequences, enabling precise manipulation of DNA.
Question 3: Which structure allows bacteria to survive extreme environmental conditions?
- Capsule
- Endospore (Correct answer)
- Pilus
- Flagellum
Correct answer: Endospore
Endospores are highly resistant dormant structures formed by certain bacteria (e.g., Bacillus) that survive heat, desiccation, and chemicals.
Question 4: In CRISPR-Cas9 gene editing, what is the role of the guide RNA?
- It cuts the DNA double strand
- It directs Cas9 to a specific DNA sequence (Correct answer)
- It repairs the cut DNA
- It transcribes the target gene
Correct answer: It directs Cas9 to a specific DNA sequence
The guide RNA (gRNA) is complementary to the target DNA sequence and directs the Cas9 protein to the correct genomic location.
Question 5: Which of the following best describes a prion?
- A virus with a DNA genome
- A misfolded protein that induces other proteins to misfold (Correct answer)
- A bacterium lacking a cell wall
- A viroid that infects plant cells
Correct answer: A misfolded protein that induces other proteins to misfold
Prions are infectious misfolded proteins that cause normal proteins to adopt their abnormal conformation, causing neurodegenerative diseases.
Question 6: What process is used in the Polymerase Chain Reaction (PCR) to separate DNA strands?
- Centrifugation
- Denaturation by heat (Correct answer)
- Enzymatic digestion
- Electrophoresis
Correct answer: Denaturation by heat
In PCR, the denaturation step uses high temperature (~95°C) to break hydrogen bonds and separate the double-stranded DNA into single strands.
Question 7: Which antibiotic targets the bacterial 50S ribosomal subunit to inhibit protein synthesis?
- Penicillin
- Tetracycline
- Erythromycin (Correct answer)
- Ciprofloxacin
Correct answer: Erythromycin
Erythromycin (a macrolide antibiotic) binds the 50S ribosomal subunit and blocks translocation, inhibiting bacterial protein synthesis.
Biology Test Biology Microbiology and Biotechnology 2
Which type of RNA carries amino acids to the ribosome during translation?