All Free Biology MCQs with Answers
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19844 questions · page 549 of 1985
5481. A single gene can be amplified by using:
- A. DNA fingerprinting
- B. Polymerase Chain Reaction
- C. Gel Electrophoresis
- D. Recombinant DNA technology
Explanation: In research or diagnosis, DNA amplification can be conducted through methods such as Polymerase chain reaction; an easy, cheap, and reliable way to repeatedly replicate a focused segment of DNA by polymerizing nucleotides, a concept that is applicable to numerous fields in modern biology and related sciences.
Correct answer: Polymerase Chain Reaction5482. Which of the following diseases CANNOT be cured by gene therapy?
- A. SCID
- B. Tuberculosis
- C. Cystic fibrosis
- D. Cancer
Explanation: Gene therapy is a medical field which focuses on the genetic modification of cells to produce a therapeutic effect or the treatment of disease by repairing or reconstructing defective genetic material. Gene therapy provides treatment for cystic fibrosis, scid and cancer. But it does not treat tuberculosis.
Correct answer: Tuberculosis5483. Which one of the following options is NOT an example of genetic engineering?
- A. Insulin-producing bacteria
- B. Oil eating bacteria
- C. Photosynthetic bacteria
- D. Metal extracting bacteria
Explanation: For bacterias to be photosynthetic they do not need to be genetically programmed. There are naturally occurring photosynthetic bacterias. But, other bacterias such as insulin-producing, oil-eating, and metal extracting ones are those that do not occur naturally; they need to be genetically programmed to do so.
Correct answer: Photosynthetic bacteria5484. Choose the best group from the following to produce transgenic plants in the laboratory:
- A. Group A
- B. Group B
- C. Group B and C
- D. Group C
Explanation: Group A is correct because it has all the tools required to engineer a plant cell. Restriction enzymes are used to cut out a piece of DNA.DNA ligases are used to engineer, take that cue out gene into the protoplast.Group B is wrong because we do not have plasmids here or any other transmitting agent; plastids are chlorophyll-containing pigments only. Group C can also not be correct for the same reason. Autoradiograph also does not have any function in the engineering of genes in plant cells.
Correct answer: Group A5485. The following picture is of _ which separates based on their size and speed.
- A. Cloning
- B. Recombinant DNA technique
- C. Cell culture
- D. Gel Electrophoresis
Explanation: Gel electrophoresis is a technique used to separate DNA fragments according to their size and speed.DNA samples are loaded into wells (indentations) at one end of a gel, and an electric current is applied to pull them through the gel. DNA fragments are negatively charged, so they move towards the positive electrode.
Correct answer: Gel Electrophoresis5486. What is Molecule "a" in the following picture?
- A. Host cell
- B. Donor cell
- C. Restriction enzyme
- D. Recombinant DNA
Explanation: When a piece of DNA from a host is cut out to be inserted into a source DNA to form a combined DNA it is called recombinant DNA.
Correct answer: Recombinant DNA5487. Restriction endonucleases found in:
- A. Viruses
- B. Bacteria
- C. Eukaryotes
- D. All of these
Explanation: Restriction endonucleases are class of enzymes found in bacteria. They act on bacteriophage viruses (viruses that attack bacteria) and they cut the viral genome from within the strand, and not across thus named as endonucleases. They are termed as Restriction enzymes as they restrict the action of viruses or chance of a viral infection
Correct answer: Bacteria5488. The enzyme that is used to cut DNA molecules in rDNA technology is called:
- A. Ligase
- B. Phosphatase
- C. Ribonuclease
- D. Restriction enzyme
Explanation: Restriction enzymes, also called restriction endonucleases, recognize a specific sequence of nucleotides in double stranded DNA and cut the DNA at a specific location.
Correct answer: Restriction enzyme5489. Genetically modified plants are:
- A. No gene
- B. No gene in transposition
- C. Widely used in gene transfer
- D. All of these options are correct
Explanation: Genetic modification of plants involves adding a specific stretch of DNA into the plant's genome, giving it new or different characteristics. This could include changing the way the plant grows, or making it resistant to a particular disease
Correct answer: Widely used in gene transfer5490. Which enzyme is administered to the patients of Severe Combined Immunodeficiency Disease (SCID)?
- A. Adenosine Deaminase (ADA)
- B. Pancreatic Enzyme
- C. ß-galactosidase
- D. ß-lactamase
Explanation: 'SCID' is due to Adenosine Deaminase (ADA) deficiency so, it is administered to overcome the deficiency. Hence, option A is correct. Pancreatic enzymes (B) partake in digestion. Beta-galactosidase (C) breaks down lactose into glucose and galactose in certain organisms. Beta-lactamase (D) is an enzyme produced by bacteria, that confers their resistance against beta-lactam drugs, such as penicillin, as it breaks down the beta-lactam ring present in these drugs.
Correct answer: Adenosine Deaminase (ADA)