1. Which enzyme is used to join two pieces of DNA?
Answer:
Explanation:
DNA ligase facilitates the joining of DNA strands by forming phosphodiester bonds.
2. Which organism is most commonly used as a host for cloning DNA fragments?
Answer:
Explanation:
E. coli is frequently used in genetic engineering as a host for cloned DNA.
3. Restriction enzymes are obtained from:
Answer:
Explanation:
Restriction enzymes are produced by bacteria to defend against viral infections by cutting up the viral DNA.
4. The technique used to make multiple copies of a DNA molecule is:
Answer:
Explanation:
PCR is a method used to amplify specific DNA sequences.
5. Plasmids are:
Answer:
Explanation:
Plasmids are small, circular DNA molecules typically found in bacteria.
6. Which of the following is NOT a tool of genetic engineering?
Answer:
Explanation:
Ribosomes are involved in protein synthesis and are not tools used in genetic engineering.
7. Bioreactors are used for:
Answer:
Explanation:
Bioreactors are vessels in which living organisms are cultivated for producing bio-products.
8. Gel electrophoresis is used to:
Answer:
Explanation:
Gel electrophoresis separates DNA fragments based on their size and charge.
9. The first recombinant DNA was constructed by:
Answer:
Explanation:
Stanley Cohen and Herbert Boyer are credited with constructing the first recombinant DNA in 1973.
10. Agrobacterium tumefaciens is exploited in genetic engineering because:
Answer:
Explanation:
Agrobacterium tumefaciens is used in plant genetic engineering due to its ability to transfer DNA to plant cells.
11. "Sticky ends" in DNA are produced by:
Answer:
Explanation:
Some restriction enzymes cut DNA in a staggered manner, producing sticky ends.
12. cDNA is synthesized from:
Answer:
Explanation:
cDNA (complementary DNA) is synthesized from mRNA using the enzyme reverse transcriptase.
13. Which of the following is a selectable marker in genetic engineering?
Answer:
Explanation:
Selectable markers, like antibiotic resistance genes, help in identifying and selecting genetically modified organisms.
14. Biotechnology has been crucial in the production of:
Answer:
Explanation:
Recombinant DNA technology has been employed to produce human insulin in bacteria.
15. Which of the following is NOT a method for introducing foreign DNA into a cell?
Answer:
Explanation:
Photosynthesis is a process plants use to convert light energy into chemical energy, and it's not related to genetic engineering.
16. "Blue-white selection" is a screening technique used in:
Answer:
Explanation:
The blue-white selection is a method to distinguish recombinant bacteria from non-recombinant ones using specific markers.
17. The process of forming multiple identical copies of a gene is termed:
Answer:
Explanation:
Cloning refers to producing multiple identical copies of a DNA segment or gene.
18. A 'genomic library' represents:
Answer:
Explanation:
A genomic library consists of a collection of DNA fragments that represent the complete genome of an organism.
19. Which enzyme helps in unwinding the DNA helix during PCR?
Answer:
Explanation:
In PCR, Taq polymerase not only synthesizes the new DNA strand but its heat-stability also allows for the denaturation step, which unwinds the DNA.
20. The term "biotechnology" was first used by:
Answer:
Explanation:
The term "biotechnology" was first coined by Karl Ereky, a Hungarian engineer, in 1919.