1. Deoxy position of deoxyribose in DNA is a
(A) 1st Carbon(B) 3rd Carbon(C) 2nd Carbon(D) 5th Carbon
Ans: 2nd position
2. Which of the following transgenic crops occupies the largest area in the world?
(A) Herbicide tolerant soybean(B) Herbicide tolerant maize(C) Insect resistant cotton(D) Insect resistant potato
Ans: Herbicide tolerant soybean
3. The gene responsible for dwarfing character in rice is
(A) Tift 23A(B) Norin 10(C) Dee-geo-woo-gen(D) Opaque 2
4. Aroma in rice is due to
(A) Acetyl choline(B) 4-benzyl pyrroline(C) 2-ethyl pyrroline(D) 2-acetyl-1-pyrroline
5. Rifampicin is a specific inhibitor of
(A) Bacterial RNA polymerase(B) RNA polymerase II(C) RNA polymerase I(D) RNA polymerase III
Ans: Bacterial RNA polymerase
- Rifampin specifically inhibits bacterial RNA polymerase, the enzyme responsible for DNA transcription
6. The Philadelphia chromosome is
(A) an example of gene amplification(B) a product of a reciprocal translocation(C) a characteristic of Burkitt’s lymphoma(D) an example of duplication
Ans: a product of a reciprocal translocation
- Deletion of one arm of chromosome 21.
- Clinical symptoms: Chronic granulocytic leukemia
7. Independently folded functional unit of a protein is called a
(A) motif(B) fold(C) domain(D) module
8. Most predominant antibody in serum is
(A) IgG(B) IgD(C) IgE(D) IgA
- IgG: Most abundant immunoglobulin, produce in the late primary response after IgM production, predominant in secondary immune response, the one and only Ig that cross placenta.
- IgA: Secretory antibody, Heaviest antibody and second most abundant
- IgM: Macroimmunoglobulin, pentamer, does not cross placenta, also known as natural antibody, first produced antibody upon infection.
- IgD: Present on surface of B-cells and in serum.
- IgE: which is responsible for allergic reactions, mediate hyper sensitivity. These are concentrated in mucous membrane, skin and lungs.
9. Scrapie is caused by
(A) Fungal protein(B) Bacterial protein(C) Plant lipoprotein(D) Prion
- Prion : infectious proteinaceous particles
- Creutzfeld-Jacob Disease: The prion protein (PrP) is an infectious protein that converts non infectious (PrP) into infectious form, which precipitates. PrP is implicated as the causative agent of the transmissible spongioform encephalopathies, including Creutzfeld-Jacob Disease.
10. Which one of the following organisms is used in Ames test?
(A) E. coli(B) Streptococcus aureus(C) Pseudomonas aerogenosa(D) Salmonella typhimurium
Ans: Salmonella typhimurium
The Ames test
- A simple and effective way to test whether a chemical is mutagenic or not.
- This test uses a strain of Salmonella bacteria that has a defective histidine synthesizing gene.
- The mutagenicity of the carcinogen can be quantified by counting the number of bacterial colonies that grow on a medium lacking histidine.