Genetic Engineering & Biotechnology MCQ Practice for UPSC & SSC

Correct Answer: (A) Functional chromosomes can be created by joining segments of DNA taken from cells of diﬀerent species.

Correct Answer: (C) Both 1 and 2

Live recombinant vector vaccines are made of a live attenuated viral or bacterial strain used as a vector to carry the gene or genes encoding the desired vaccine antigens. In these vaccines live viral or bacterial vector is genetically engineered to express a variety of exogenous antigens in the cytoplasm of targeted T cells. Live recombinant vector vaccines have a number of attractive features, including the ability to stimulate both humoral and cell-mediated immunity. Recombinant vector vaccines (platform-based vaccines) act like a natural infection, so they're especially good at teaching the immune system how to ﬁght germs.
Note: Recombinant DNA Technology is used to cut a known DNA sequence from one organism and introduce it into another organism thereby altering the genotype of the recipient. Foreign DNA sequences can be introduced into bacteria, yeast, viruses, plant and animal cells. Thus, genetic engineering (or recombinant DNA technology) allows selected individual gene sequences to be transferred from an organism into other and also between non-related species.
Steps in producing recombination DNA: → Identiﬁcation and isolation of genetic material → Fragmenting the obtained DNA → Isolation of desired DNA fragments → Ampliﬁcation of gene of interest → Ligation of DNA fragmentation into the vector → Transfer of recombinant DNA into the host cell/organism → Obtaining the foreign gene product → Downstream processing.

Correct Answer: (A) A molecular scissors used in targeted gene editing

Cas9 protein (CRISPR associated protein 9) is actually a molecular scissors used in targeted gene editing. Its main function is to cut DNA and therefore it can alter a cell’s genome. In CRISPR-Cas9 gene editing technique, the ‘CRISPR’ stands for ‘clustered regularly interspaced short palindromic repeats’, which are specialized stretches of DNA. While the ‘Cas9’ is an enzyme that acts like a pair of molecular scissors capable of cutting strands of DNA. This technology was adapted from the natural defence mechanisms of bacteria and archaea. By delivering the Cas9 molecule complexed with a synthetic guide RNA (gRNA) into a cell, the cell’s genome can be cut at a desired location, allowing existing genes to be removed and/or new ones added.

Correct Answer: (A) 1, 2 and 4

RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression or translation, by neutralizing targeted mRNA (messenger RNA) molecules. Hence, it is used in developing gene silencing therapies. RNAi is being explored as a form of treatment for a variety of diseases, including HIV/AIDS, hepatitis, Huntington disease and cancer. Many studies have demonstrated that RNAi can provide a more speciﬁc approach to inhibit tumor growth by targeting oncogenes (cancer-related genes). Using RNAi technology, scientists have made major breakthroughs in introducing resistance to many viruses in various crops. Thus, RNAi technology can be used to produce crop plants that are resistant to viral pathogens. Thus statements 1, 2 and 4 are correct while, statement 3 is not correct because in development of hormone replacement therapies there is no role of RNA interference.

Correct Answer: (A) 1 only

Mitochondrial Replacement Therapy (MRT), sometimes called mitochondrial donation, is the replacement of mitochondria in one or more cells to prevent or ameliorate disease. MRT originated as a special form of in vitro fertilization in which some or all of the future baby's mitochondrial DNA (mt DNA) comes from a third party. This technique is used in cases when mothers carry genes for mitochondrial diseases. The therapy is approved for use in the United Kingdom. At present, there are three MRT techniques in use: maternal spindle transfer (MST); pronuclear transfer (PNT); and the newest technique, polar body transfer (PBT). Mitochondrial donation can be performed either prior to or shortly after fertilization. In both cases, this is before the fertilized egg becomes an embryo. Hence, statement 1 is correct. Mitochondrial diseases may be caused by mutations (acquired or inherited) in mitochondrial DNA (mt DNA), or in nuclear genes that code for mitochondrial components. Nuclear DNA has two copies per cell (except for sperm and egg cells), one copy being inherited from the father and the other from the mother. Mitochondrial DNA, however, is inherited from the mother only (with some exceptions). Typically, humans inherit mitochondria and mitochondrial DNA from their mothers only. But researchers have identiﬁed some individuals who inherited mt DNA from both parents (as per a research paper published in November 2018). Hence, statement 2 is incorrect.

Correct Answer: (B) A clone is produced asexually

Any organism whose genetic information is identical to that of a parent organism is known as a clone. They have produced asexually and are identical to parent in all Any organism characters. The process to obtain clone is called as cloning. Identical twins are not clones and two clones of an organism are identical.

Correct Answer: (C) Fertilization takes place outside the mother’s body

Females, who are not able to conceive a natural pregnancy, their eggs are artificially fertilized. The child born by IVF technique is known as ‘Test-tube baby’. Sperm-egg fertilization which is naturally in female fallopian tubes, takes place in petridishes artiﬁcially outside of mother’s body. After these fertilized embryos are implanted in the uterus of a female in between 16 to 48 hours for getting new oﬀspring.

Correct Answer: (D) 1, 2 and 3

Through genetic engineering, disease resistance, growth enhancement and animal cloning have been achieved successfully but human cloning has not got proper fruitful results because it is controversial and banned.

Correct Answer: (D) Ochoa

Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells, discovered in 1946 by Joshua Lederberg and Edward Tatum. Morgan was the ﬁrst to establish the chromosome theory of inheritance. He used fruit ﬂies with eye colour mutations to demonstrate sex- linked inheritance patterns. Discovered by Arthur Kornberg in 1956, it was the ﬁrst known DNA polymerase (and, indeed, the ﬁrst known of any kind of polymerase). It was initially characterized in E. coli and is ubiquitous in prokaryotes. Hargobind Khorana was an Indian-American biochemist who shared the 1968 Nobel Prize in Physiology or Medicine with Marshall W. Nirenberg and Robert W. Holley for research that helped to show how the order of nucleotides in nucleic acids, which carry the genetic code of the cell, control the cell’s synthesis of proteins.

Correct Answer: (C) Reproductive cloning of animals

Somatic cell nuclear transfer (SCNT) can be used in embryonic stem cell research, or in regenerative medicine where it is sometimes referred to as ‘therapeutic cloning’. It can also be used as the ﬁrst step in the process of reproductive cloning. The nucleus of the somatic cell is inserted into the enucleated (after removal of nucleus) egg cell.

Correct Answer: (A) Monoclonal antibodies

Hybridoma technology is a technology of forming hybrid cell lines (called hybridomas) by fusing an antibody– producing B cell with a myeloma (B cell cancer) cell that is selected for its ability to grow in tissue culture and for an absence of antibody chain synthesis. The antibodies produced by the hybridoma are all of a single speciﬁcity and are therefore monoclonal antibodies (in contrast to polyclonal antibodies). The production of monoclonal antibodies was invented by César Milstein and Georges J. F. Köhler in 1975. They shared the Nobel Prize in 1984 for medicine and physiology with Niels Kaj Jerne, who made other contributions to immunology.

Correct Answer: (B) developing genetically modiﬁed crop plants

Bollgard I Bt-cotton (single-gene technology) is India's ﬁrst biotech crop technology approved for commercialization in India in 2002, followed by Bollgard II – double-gene technology in mid-2006, by the Genetic Engineering Approval Committee (GEAC), the Indian regulatory body for biotech crops.
Bollgard I cotton provides in-built protection for cotton against destructive American Bollworm Heliothis Armigera infestations, and contains an insecticidal protein from a naturally occurring soil microorganism, Bacillus thuringiensis (Bt). Bollgard II technology contains a superior double-gene technology – Cry 1 Ac and Cry 2 Ab which provides protection against bollworms and Spodoptera caterpillar, leading to better boll retention, maximum yield, lower pesticides costs, and protection against insect resistance. Both, Bollgard II and Bollgard I insect-protected cotton are widely planted around the world as an environment-friendly way of controlling bollworms.

Correct Answer: (A) To make it pest-resistant

Bt. brinjal is a transgenic brinjal created by inserting a gene ‘Cry 1 Ac’ from the soil bacterium ‘Bacillus thuringiensis’ into brinjal. Bt. brinjal has been developed to give resistance against lepidopteran insects like the brinjal shoot-borer Leucinodes orbonalis and fruit-borer Helicoverpa armigera. Bt. brinjal has generated much debate in India. The promoters say that Bt. brinjal will be beneﬁcial to small farmers because it is insect resistant, increases yields etc. On the other hand, concerns about Bt. brinjal relates to its possible adverse impact on human health and bio-safety, livelihoods and biodiversity. In India Bt. brinjal was developed by the Maharashtra Hybrid Seeds company (Mahyco). Despite the conduct of ﬁeld trials from 2002-2006, a moratorium was issued in October 2009 and a government ban was implemented in February, 2010.

Correct Answer: (B) 2 only

GM mustard developed in India, also known as Dhara Mustard Hybrid-11 (DMH-11), is a genetically modiﬁed hybrid variety of the mustard species Brassica juncea. It was developed by Prof. Deepak Pental (University of Delhi) with the aim of reducing India’s demand for edible oil imports. His team introduced several genes from a soil bacterium, Bacillus amyloliquefaciens, into the mustard that allow the plant cross-pollination and hybridization. Then they cross-pollinated Indian variety with European variety to make new hybrid called DMH-11. The above DMH-11 has been developed by the scientists of ‘Center for Genetic Manipulation of Crop Plants’ of Delhi University. Hence, only statement 2 is correct.
Note: Genetically modiﬁed crops (GMCs, GM crops, or biotech crops) are plants used in agriculture, the DNA of which has been modiﬁed using genetic engineering techniques. In most cases, the aim is to introduce a new trait to the plant which does not occur naturally in the species. Examples in food crops include resistance to certain pests, diseases or environmental conditions, reduction of spoilage or resistance to chemical treatments (e.g., resistance to an herbicide), to enable them to withstand drought, to increase the nutritive value of the produce, to increase their shelf life, or improving the nutrient proﬁle of the crop.

Correct Answer: (D) 1, 2 and 3

Genome sequencing plays an important role in the agriculture sector. It can be used to identify genetic indicators, which is essential for developing properties such as disease resistance and drought-tolerance in crops. Genome sequencing can help in reducing the time required to develop new varieties of crops. Also, it can be used to understand the host pathogen relationship in crops.

Correct Answer: (D) 1, 2 and 3

Biopesticides fall into three major classes: Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient. Microbial pesticides can control many diﬀerent kinds of pests, although each separate active ingredient is relatively speciﬁc for its target pests. For example, there are fungi that control certain weeds and other fungi that kill speciﬁc insects. Neem is the best example as biopesticide among ﬂowering plants.

Correct Answer: (A) Bacillus thuringiensis

Bacillus thuringiensis (Bt) is a Gram-positive, soil-dwelling bacterium which naturally produces a toxin that is fatal to certain herbivorous insects. The toxin produced by B. thuringiensis has been used as an insecticide spray since 1920 and is commonly used in organic farming. Bt is also the source of the genes used to genetically modify a number of food crops so that they produce toxin on their own to deter various insects or pests. The toxin is lethal to several orders of insects, including Lepidoptera (butterﬂies, moths and skippers); Diptera (ﬂies) and Coleoptera (beetles).

Genetic Engineering and Biotechnology MCQs with Explanations

Practice MCQ Questions