All Free Biology MCQs with Answers
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19844 questions · page 554 of 1985
5531. Any DNA molecule having foreign DNA is called:
- A. Mutant
- B. Recombinant
- C. Crossing over
- D. All of the above
Explanation: Recombinant DNA is the hybrid DNA made by two or more DNA molecules joined together. So B is the correct option.
Correct answer: Recombinant5532. The technique of DNA fingerprinting has been used to identify people in crime, accidents, and family relationships. To analyze the DNA of members of the same family, it is necessary to examine samples of their tissues for:
- A. Similarities in the nucleotide uracil
- B. Similarities in the deoxyribose sugar
- C. Similarities in nucleotide base pairs
- D. RNA differences
Explanation: Similarities in the nucleotide base pairs is the correct answer. Uracil is not related to DNA and is a nucleotide of RNA.The structure of deoxyribose sugar is the same in all.
Correct answer: Similarities in nucleotide base pairs5533. Which kind of therapy was given in 1990 to a four year girl with Adenosine Deaminase (ADA) enzyme deficiency?
- A. Gene therapy
- B. Chemotherapy
- C. Immunotherapy
- D. Radiation therapy
Explanation: Gene therapy is a technique of genetic engineering which involves the replacement of a faulty/disease-causing gene by a normal healthy functional gene. The first clinical ex-vivo gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) enzyme deficiency. This enzyme is very important for the immune system to function and the deficiency of this enzyme can lead to severe combined immune deficiency (SCID).
Correct answer: Gene therapy5534. Which of the following characteristics make plasmid DNA useful for researchers?
- A. Ability to incorporate cloned DNA
- B. Ability to replicate independently of chromosomal DNA
- C. Ability to be isolated from the host's genomic DNA
- D. All of the above
Explanation: Plasmids are critical tools in molecular biology due to their ability to incorporate foreign DNA, replicate independently, and be easily isolated. Each characteristic plays a vital role: incorporating DNA allows for the study of specific genes; autonomous replication ensures that once introduced, the plasmid and inserted DNA are maintained across cell generations; and isolation facilitates the analysis and manipulation of the DNA. Option D is correct as it encompasses all these beneficial properties. Options A, B, and C, while true, only partially represent the usefulness of plasmids.
Correct answer: All of the above5535. Recombinants contains DNA from
- A. Two different sources
- B. A single source
- C. Two identical sources
- D. Three identical sources
Explanation: Recombinant DNA technology is the process of joining together DNA from two different species, resulting in a new genetic combination that can be used in various fields such as science, medicine, agriculture, and industry. The key aspect is that the DNA must come from two distinct sources to create the recombinant DNA molecule. Options B, C, and D are incorrect because they involve DNA from the same source or multiple identical sources, which does not meet the criteria for recombination.
Correct answer: Two different sources5536. Which of the following are the genetically engineered bacteria that are used to make human growth hormone and insulin for diabetics?
- A. Pneumococcus
- B. E. Coli
- C. Rhizobium
- D. Nostoc
Explanation: E.coli is correct. E. coli has been programmed to make human growth hormones for the treatment of growth deficiencies and insulin for diabetics.Scientists produce insulin using E.coli by inserting the human insulin gene into the bacteria's DNA, causing the E. coli to act as a "factory" for insulin. First, the human insulin gene is extracted and put into a plasmid (a small, circular piece of DNA). This recombinant plasmid is then introduced into E. coli bacteria through transformation.
Correct answer: E. Coli5537. It serves as a vector in genetic engineering.
- A. Plastids
- B. Plasmid
- C. Nucleoid
- D. Pili
Explanation: A plasmid is a small fragment of extra genetic material, double-stranded DNA. It is self-replicating and not associated with growth and metabolism. Plasmids serve as vectors in genetic engineering.Hence, option B is correct.
Correct answer: Plasmid5538. A virus enters into the body of host & intends to produce DNA from RNA.Which enzyme is required for this process?
- A. Transcriptase
- B. Reverse transcriptase
- C. Oxidoreductase
- D. Ligases
Explanation: Reverse transcriptase is responsible for conversion of single stranded RNA into double stranded DNA. Hence this option is correct.
Correct answer: Reverse transcriptase5539. The technique used for identification of criminals is called:
- A. DNA fingerprinting
- B. Fingerprinting
- C. Handwriting analysis
- D. Voiceprint analysis
Explanation: This is the correct answer. DNA fingerprinting is a forensic technique used to identify individuals based on their unique DNA profiles. It involves analyzing specific regions of DNA that vary between individuals, creating a unique pattern that can be used for identification.
Correct answer: DNA fingerprinting5540. Autoclave chambers are used for _ of surgical instruments?
- A. Sterlization
- B. Filtration
- C. Desiccation
- D. Radiation
Explanation: Autoclave chambers, also known as autoclaves or steam sterilizers, are used to sterilize surgical instruments and other medical equipment by exposing them to high-pressure steam at a temperature of around 121°C (250°F) for a specified period. This process kills all forms of microbial life, including bacteria, viruses, and spores, making the instruments safe for use in surgical procedures.
Correct answer: Sterlization