Molecular Biology And Genetics — Part 2 MCQs with Explanations

DNA polymerase I is the correct answer to “The RNA primer synthesized during the replication process in bacteria is removed by”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

$${3 \over 8}$$ is the correct answer to “A disease is inherited by a child with a probability of $${1 \over 4}$$. In a family with two children, the probability that exactly one sibling is affected by this disease is”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Removal of intervening protein sequences from the translated protein is the correct answer to “The term 'protein splicing' refers to”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

P-4, Q-2, R-3, S-1 is the correct answer to “Match the terms in Group I with the ploidy in Group II . Group I Group II P. Disome 1. 2n + 1 Q. Monosome 2. 2n - 1 R. Nullisome 3. n - 1 S. Trisome 4. n + 1”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

50% ovules will have XXX endosperm and XX embryo, while the other 50% will have XXY endosperm and XY embryo is the correct answer to “A dioecious plant has XX sexual genotype for female and XY for male. After double fertilization, what would be the genotype of the embryos and endosperms”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

CCU is the correct answer to “An in vitro translation system can synthesize peptides in all three reading frames of the RNA template. When 5' - UCUCUCUC-(UC) n -UCUCUCUC - 3' was used as the template in this in vitro translation system, the synthesized peptides contained 50% each of serine and leucine. When 5' - CCUCCUCCU-(CCU) n -CCUCCU - 3' was used as the template, the synthesized peptides contained 33.3% each of serine, leucine, and proline. Deduce the codon for proline.”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Termination is the correct answer to “During protein synthesis, tRNAs are not involved in”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Single stranded RNA is the correct answer to “If the nucleotide composition (%) of a viral genome is A = 10, U = 20, C = 40 and G = 30, which one of the following is this genome”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Q, R and T is the correct answer to “Which set of the following events occurs during the elongation step of translation? P. Attachment of mRNA with the smaller subunit of ribosome Q. Loading of correct aminoacyl-tRNA into the A site. R. Formation of a peptide bond between the amino acyl-tRNA in the A site and the peptide chain that is attached to the peptidyl-tRNA in the P site. S. Dissociation of the ribosomal subunits. T. Translocation of peptidyl-tRNA from the A site to the P site of the ribosome.”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Relative position: Y-W-X Distances: Y-W = 5 map units, W-X = 11 map units is the correct answer to “In a genetic cross between the genotypes WWXX and wwxx, the following phenotypic distributions were observed among the F 2 progeny: WX, 562; wx, 158; Wx, 38; and wX, 42. Likewise, a cross between XXYY and xxyy yielded the following results: XY, 675; xy, 175; Xy, 72; and xY, 78. Similarly, a cross between WWYY and wwyy yielded: WY, 292; wy, 88; Wy, 12; and wY, 8. In all the genotypes, capital letters denote the dominant allele. Assume that the F 1 progeny were self-fertilized in all three crosses. Also, double cross-over does not occur in this species. Which of the following is correct”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

N7 of purine and C4 of pyrimidine is the correct answer to “The major groove of DNA is lined by”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Terminal deoxynucleotidyl transferase is the correct answer to “An example for template independent DNA polymerase is”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Local conservation of gene order is the correct answer to “Synteny refers to”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

P, Q and R only is the correct answer to “Which of the following processes can increase genetic diversity of bacteria in nature? P. Conjugation Q. Transformation R. Transduction S. Transfection”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Both (A) and (R) are true and (R) is the correct reason for (A) is the correct answer to “"Determine the correctness or otherwise of the following Assertion (A) and the Reason (R) . Assertion: N-methyl-N'-nitro-N-nitrosoguanidine (NTG) is an effective chemical mutagen. Reason: Mutations induced by NTG mainly are the GC → AT transitions."”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

5'-AUGGACCAGA-3' is the correct answer to “If a segment of a sense strand of DNA is 5'-ATGGACCAGA-3', then the resulting RNA sequence after transcription is”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Anti, and 2'-endo in B form DNA is the correct answer to “Which of the following statements with respect to the orientation of the nitrogenous bases to the pentose sugars, and the puckering of the sugar, is correct”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

46 or 50 is the correct answer to “Of the two diploid species, species I has 36 chromosomes and species II has 28 chromosomes. How many chromosomes would be found in an allotriploid individual”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Both mutagenicity and carcinogenicity of a chemical is the correct answer to “Ames test is used to determine”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Nonsense mutation is the correct answer to “A mutation in a gene that codes for a polypeptide results in a variant polypeptide that lacks the last three amino acids. What type of mutation is this”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

P-3, Q-4, R-2, S-1 is the correct answer to “Match the entries in Group I with the entries in Group II . Group I Group II P. RNAse P 1. Polyadenylation Q. RNase H 2. Splicing R. snRNAs 3. Ribozymes S. CstF 4. DNA-RNA hybrids”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

187, 10.69 is the correct answer to “Topological winding number of a 2.0 kb covalently closed circular DNA was found to be 191 with a writhing number of -4. Hence, its linking number and the number of base pair per turn when the molecule is laid flat on the surface is . . . . . . . . and . . . . . . . ., respectively.”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Phenylalanine hydroxylase is the correct answer to “PKU is one of the best-known hereditary disorders in amino acid metabolism. The defect is attributed to a lesion in one of the following enzymatic activities:”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Transfer RNA gene is the correct answer to “A truncated polypeptide is synthesized due to a nonsense mutation. Where would you introduce another mutation to obtain a full-length polypeptide”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Aneuploid is the correct answer to “Diploid Drosophila has eight chromosomes. Which one of the following terms should not be used to describe Drosophila with sixteen numbers of chromosomes”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

11 is the correct answer to “How many 3-tuples are possible for the following amino acid sequence”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

The proper folding of newly synthesized proteins is the correct answer to “Molecular chaperones are class of proteins that facilitate”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Avidin is the correct answer to “Which one of the following is not a therapeutic agent based on nucleic acid for the treatment of genetic disorders”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

RNA polymerase I is the correct answer to “The enzyme that transcribes the eukaryotic genes encoding precursor ribosomal RNAs (pre-rRNAs) of 28S, 18S and 5.8S rRNAs is”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Apoptosis is the correct answer to “Caspases are involved in the process of”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Q, R is the correct answer to “Which of the following statements are true with respect to a special complex called 'dicer'? P. It consists of deoxyribonuclease and DNA fragments. Q. It consists of ribonuclease and RNA fragments. R. It is involved in gene silencing. S. It triggers apoptosis.”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Both DNA gyrase and DNA topoisomearse I introduce negative supercoils is the correct answer to “During transcription,”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Both the repressor and cAMP-CAP complex remain bound to their respective binding sites is the correct answer to “What will be the binding status of regulatory proteins in lac operon when concentrations of both lactose and glucose are very low in the culture medium”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

A triphosphate group in mRNAs and a monophosphate group in tRNAs is the correct answer to “The 5' ends of the mature forms of the prokaryotic mRNAs and tRNAs are”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Nucleosome free is the correct answer to “Nuclease-hypersensitive sites in the chromosomes are sites that appear to be”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

20100 is the correct answer to “How many different protein sequences of 100 residues can be generated using 20 standard amino acids”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

About 68% is the correct answer to “The G + C content of bacteriophage M13 double stranded DNA is 68%. What would you expect the G + C content of its mRNA”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

All of the above is the correct answer to “Efficient expression of a heterologous protein product is influenced by”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Major groove of the double stranded DNA is the correct answer to “The 4-amino or 4-keto group of pyrimidine bases is located in the”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.

Methylation is the correct answer to “Which one of the following modifications is common to both protein and DNA”. This question is standard in competitive examination syllabi for Molecular Biology And Genetics.