All Free Biology MCQs with Answers
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19844 questions · page 543 of 1985
5421. Somatic embryos are encapsulated in a protective:
- A. Gel
- B. Hyrdated gel
- C. Electrophoresis
- D. Sol
Explanation: Somatic embryos that are encapsulated in a protective hydrated gel (and sometimes called artificial seeds)
Correct answer: Hyrdated gel5422. A technique for the culturing of plant tissues is called:
- A. Cell culture
- B. Meristem culture
- C. Anther culture
- D. Cell suspension culture
Explanation: A cell suspension or suspension culture is a type of cell culture in which single cells or small aggregates of cells are allowed to function and multiply in an agitated growth medium, thus forming a suspension
Correct answer: Cell suspension culture5423. Genetic engineering is expected to increase:
- A. Sensitivity
- B. Fertility
- C. Productivity
- D. Insensitivity
Explanation: Genetically, engineered bacteria have been used to clean up environmental pollutants, increase the fertility of the soil, and kill insect pests.
Correct answer: Fertility5424. The enzyme that can be used to treat a human lysosome shortage disease is:
- A. B-galactosidase
- B. a-galactosidase
- C. Galactosidase
- D. a and B-galactosidase
Explanation: Tens of grams of a-galactosidase, an enzyme that can be used to treat a human lysosome storage
Correct answer: a-galactosidase5425. The growth of a tissue in an artificial liquid culture medium is called:
- A. Tissue culture
- B. Cloning
- C. Angioplasty
- D. Gene therapy
Explanation: Tissue culture (TC) is the cultivation of plant cells, tissues, or organs on specially formulated nutrient media. Under the right conditions, an entire plant can be regenerated from a single cell. Plant tissue culture is a technique that has been around for more than 30 years.
Correct answer: Tissue culture5426. Gene of interest with vector:
- A. Recombinant DNA
- B. Cuts double stranded DNA
- C. Four or six
- D. Bind by supplementary base pair
Explanation: First the gene of interest is cut and paste into a vector, such as a plasmid, to form recombinant DNA. The recombinant DNA is then inserted into a host which makes copies of the gene.
Correct answer: Recombinant DNA5427. Sticky ends are:
- A. Bind by supplementary base pair
- B. An expression system
- C. Four or six
- D. Complementary ends of DNA
Explanation: The single stranded but complementary ends of the two DNA molecules are called "sticky ends" because they can bind by complementary base pairing. They, therefore, facilitate the insertion of foreign DNA into vector DNA.
Correct answer: Complementary ends of DNA5428. Cuts the plasmid:
- A. Chimaeric DNA
- B. Takes up recombined plasmid
- C. DNA ligase
- D. Cloned genes
Explanation: DNA ligase is a type of enzyme that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond. It plays a role in repairing single-strand breaks in duplex DNA in living organisms, but some forms may specifically repair double-strand breaks
Correct answer: DNA ligase5429. Host cell takes up:
- A. DNA ligase
- B. Cloned genes
- C. Recombined plasmid
- D. Chimaeric DNA
Explanation: Bacterial cells take up recombinant plasmid, especially, if they are treated with calcium chloride to make them more permeable.
Correct answer: Recombined plasmid5430. pBR 322 is:
- A. Antibiotic resistance genes for tetracycline and ampicillin
- B. Chimaeric DNA
- C. Takes up recombined plasmid
- D. DNA ligase
Explanation: pBR 322 has antibiotic resistance genes for tetracycline as well as ampicillin.
Correct answer: Antibiotic resistance genes for tetracycline and ampicillin