Question

Question. In E.coli, the lac operon gets switched on whenA. lactose is present and it binds to the repressor.B. repressor binds to operator.C. RNA polymerase binds to the operator.D. lactose is present and it binds to RNA polymerase. Answer: A. lactose is present and it binds to the repressor.

Question. Which of the following is correct about mature RNA in eukaryotes?A. Exons and introns do not appear in the mature RNA.B. Exons appear, but introns do not appear in the mature RNA.C. Introns appear, but exons do not appear in the mature RNA.D. Both exons and introns appear in the mature RNA. Answer: B.

Question. The promoter site and the terminator site for transcription are located atA. 3′ (downstream) end and 5′ (upstream) end, respectively of the transcription unitB. 5′ (upstream) end and 3′ (downstream) end, respectively of the transcription unitC. the 5′ (upstream) end of the transcription unitD. the 3′ (downstream) end of the transcription unit Answer: B.

Question. Which of the following criteria must a molecule fulfil to act as a genetic material?(i) It should not be able to generate its replica(ii) It should chemically and structurally be stable(iii) It should not allow slow mutation(iv) It should be able to express itself in the form of Mendelian CharactersA. (i) and (ii)B. (ii)

Question. Which of the following combination of chromosome numbers represents the correct sex determination pattern in honey bees?A. Male 32, Female 16B. Male 16, Female 32C. Male 31, Female 32D. Female 32, Male 31 Answer: B. Male 16, Female 32

Question. In human beings, where genotype AABBCC represents dark skin colour, aabbcc represents light skin colour and AaBbCc represents intermediate skin colour; the pattern of genetic inheritance can be termed as:A. Pleiotropy and codominanceB. Pleiotropy and incomplete dominanceC. Polygenic and qualitative inheritanceD. Polygenic and quantitative inheritance Answer: D. Polygenic and quantitative inheritance

Question. Which of the following amino acid substitution is responsible for causing sickle cell anemia?A. Valine is substituted by Glutamic acid in the α globin chain at the sixth positionB. Valine is substituted by Glutamic acid in the β globin chain at seventh positionC. Glutamic acid is substituted by Valine in the α globin chain

Question. Which of the following statements indicates parallelism in genes and chromosomes?(i) They occur in pairs(ii) They segregate during gamete formation(iii) They show linkage(iv) Independent pairs segregate independentlyA. (i) and (iii)B. (ii) and (iii)C. (i), (ii) and (iii)D. (i), (ii) and (iv) Answer: D. (i), (ii) and (iv)

Question. How many types of gametes would be produced if the genotype of a parent is AaBB?A. 1B. 2C. 3D. 4 Answer: B. 2

Question. The thalamus contributes to the fruit formation inA. banana.B. orange.C. strawberry.D. guava. Answer: C. strawberry.