Module 6.1: Gene Cloning Strategy

Start Here Introduction ▾

Welcome! Gene Cloning Strategy (6.1) — 19 questions across 1 tests.

How the tests are arranged

Test 1 (6.1) — Gene Cloning Strategy

How to use

Tap any test below — it opens on its own full screen. Use ← All tests at the top to come back.
Answer the questions, then Submit to see your score.
Tap 📋 View Solution under any question for a full explanation.

Open Review at the bottom for a quick revision list of every question with its correct answer.

All 19 Questions Review ▾

Quick revision: every question with its correct answer. For the full explanation, open the relevant test and tap View Solution.

6.1 Gene Cloning Strategy — Test 1

Q1. A 200-nt single-stranded DNA has 40% GC (so C=40), with A = twice T. Counts of A and G are:✓ 40 and 30

Q2. An RNA molecule can be radioactively labelled DURING synthesis using:✓ α-³²P-ATP (incorporated into the backbone)

Q3. cDNA is:✓ Complementary DNA made from an mRNA template by reverse transcriptase

Q4. The COVID-19 RT-PCR diagnostic test is based on:✓ Polymerase chain reaction (after reverse transcription)

Q5. Mixing 14N DNA (organism A) with equal 15N DNA (organism J); 5% renatures to hybrid density. The fraction of common (shared) sequences is about:✓ 10%

Q6. On agarose gel electrophoresis, which migrates fastest among forms of the same plasmid?✓ Supercoiled (covalently closed circular)

Q7. If radioactive ³⁵S is added to E. coli medium, the label localizes mainly in:✓ Enzymes/proteins (Met, Cys contain S)

Q8. In DNA isolation, protein and RNA are removed respectively by:✓ Protease and ribonuclease

Q9. The function of loading dye in gel electrophoresis is to:✓ Track migration AND add density so the sample sinks into the well

Q10. Pulsed-field gel electrophoresis (PFGE) is used to separate:✓ Very large DNA fragments / whole chromosomes

Q11. Which radioactive label is used to study DNA synthesis in cells?✓ ³H-thymidine (or α-³²P-dNTP)

Q12. The Meselson-Stahl experiment (1958) used:✓ ¹⁵N labelling and CsCl density-gradient centrifugation

Q13. Hershey and Chase grew their phages on medium containing radioactive:✓ Phosphorus (³²P for DNA) and sulfur (³⁵S for protein)

Q14. At higher voltage, DNA fragments migrate faster mainly due to:✓ Increased current/field strength driving migration

Q15. Which sequence has NO DNA-binding motif (is a made-up motif)?✓ 'Isoleucine zipper' (not a real motif)

Q16. Which DNA is most commonly used in molecular systematics/phylogenetics across many taxa?✓ Ribosomal DNA / rRNA genes

Q17. Which radioisotope is NOT suitable for DNA-labelling studies?✓ ¹⁵N (a stable, non-radioactive isotope)

Q18. Which agent is used for colorimetric DNA quantification?✓ Diphenylamine (Dische reaction)

Q19. A double crossover within a paracentric inversion loop produces meiotic products that are largely:✓ Inviable (one dicentric, one acentric among products)