Test your knowledge of biotechnology and its applications in agriculture, medicine, and ethical considerations with these multiple-choice questions.
Test Your Knowledge
Showing questions 21 - 40 of 49
21. The nematode *Meloidegyne incognitia* is known to infect the roots of which plant, causing a great reduction in yield, and was targeted using an RNAi strategy?
A nematode called *Meloidegyne incognitia* infects the roots of tobacco plants and causes a great reduction in yield, and an RNAi-based strategy was adopted to prevent this infestation.
22. In the RNAi strategy to protect plants from nematode infestation, what type of vector was used to introduce nematode-specific genes into the host plant?
*Agrobacterium* vectors were used to introduce nematode-specific genes into the host plant, which then produced both sense and anti-sense RNA.
23. A major advantage of recombinant therapeutics over similar products isolated from non-human sources, as highlighted in the sources, is that they:
Recombinant therapeutics do not induce unwanted immunological responses, which is a common issue with similar products isolated from non-human sources.
24. Before genetically engineered insulin became available, insulin for diabetic patients was commonly extracted from the pancreas of:
Insulin used for diabetes was earlier extracted from the pancreas of slaughtered cattle and pigs.
25. Mature human insulin is composed of:
Insulin consists of two short polypeptide chains: chain A and chain B, that are linked together by disulphide bridges.
26. What extra polypeptide stretch is present in pro-insulin but is removed during its maturation into active insulin in mammals, including humans?
In mammals, insulin is synthesized as a pro-hormone which contains an extra stretch called the C peptide. This C peptide is not present in the mature insulin and is removed during maturation.
27. Which American company successfully prepared and produced human insulin chains using *E. coli* in 1983?
In 1983, Eli Lilly, an American company, prepared two DNA sequences corresponding to the A and B chains of human insulin and introduced them into plasmids of *E. coli* to produce the insulin chains separately.
28. Gene therapy is best described as a collection of methods that allows:
Gene therapy is a collection of methods that allows the correction of a gene defect that has been diagnosed in a child/embryo, where genes are inserted into a person’s cells and tissues to treat a disease.
29. The first clinical gene therapy was performed in 1990 for a 4-year-old girl suffering from which hereditary disease?
The first clinical gene therapy was given in 1990 to a 4-year-old girl with adenosine deaminase (ADA) deficiency.
30. Besides gene therapy, what are the other two traditional approaches mentioned for treating ADA deficiency, noting their limitation of not being completely curative?
ADA deficiency can be cured by bone marrow transplantation in some cases, or treated by enzyme replacement therapy; however, both approaches are not completely curative.
31. In the initial gene therapy for ADA deficiency, a functional ADA cDNA was introduced into lymphocytes using a retroviral vector. What was the main drawback of this approach?
A functional ADA cDNA (using a retroviral vector) was introduced into lymphocytes, which were then returned to the patient. However, as these cells are not immortal, the patient required periodic infusion of such genetically engineered lymphocytes.
32. According to the sources, a potential permanent cure for ADA deficiency could involve introducing the ADA-producing gene into cells at which stage?
If the gene isolated from marrow cells producing ADA is introduced into cells at early embryonic stages, it could be a permanent cure.
33. Which of the following techniques are explicitly mentioned as serving the purpose of early diagnosis of diseases, especially when conventional methods are not effective?
Recombinant DNA technology, Polymerase Chain Reaction (PCR), and Enzyme Linked Immuno-sorbent Assay (ELISA) are some of the techniques that serve the purpose of early diagnosis.
34. PCR (Polymerase Chain Reaction) is particularly useful in early disease diagnosis because it can:
Very low concentrations of bacteria or viruses can be detected by amplification of their nucleic acid by PCR, even when symptoms are not yet visible.
35. In the molecular diagnosis method using a radioactive probe and autoradiography to detect a mutated gene in a clone of cells, how is the clone with the mutated gene identified?
A single-stranded DNA or RNA probe tagged with a radioactive molecule is allowed to hybridise to its complementary DNA. The clone having the mutated gene will not appear on the photographic film because the probe will not have complementarity with the mutated gene.
36. ELISA (Enzyme Linked Immuno-sorbent Assay) is based on the principle of:
ELISA is based on the principle of antigen-antibody interaction. Infection by a pathogen can be detected by the presence of antigens or by detecting the antibodies synthesized against the pathogen.
37. Animals whose DNA has been manipulated to possess and express an extra (foreign) gene are known as:
Animals that have had their DNA manipulated to possess and express an extra (foreign) gene are known as transgenic animals.
38. What percentage of all existing transgenic animals are mice, according to the sources?
Although transgenic rats, rabbits, pigs, sheep, cows, and fish have been produced, over 95 per cent of all existing transgenic animals are mice.
39. Transgenic animals are specifically designed to allow the study of normal physiology and development by investigating:
Transgenic animals can be specifically designed to allow the study of how genes are regulated, and how they affect the normal functions of the body and its development, for example, complex factors involved in growth like insulin-like growth factor.
40. Transgenic animals serve as models for which of the following human diseases to facilitate the investigation of new treatments?
Transgenic models exist for many human diseases such as cancer, cystic fibrosis, rheumatoid arthritis, and Alzheimer’s, to investigate new treatments.