Hybridization of mRNA with DNA can reveal which segment of the DNA are introns and which segment are exons. When the magnification is high enough to see the molecule, the introns appear as
1. Single stranded loops in a double stranded molecule
2. Separate fragments
3. Triple stranded nucleic acid molecules
4. Barr bodies
Match each item in Column I with one item in Column II and chose your answer from the codes given below:
Column I Column II
(mRNA codons) (Amino acid)
I. GUG 1. Tryptophan
II. UGG 2. Valine
III. UAC 3. Glutamic acid
IV. GAG 4. Tyrosine
Codes:
I II III IV
A. 1 2 3 4
B. 2 1 4 3
C. 2 1 3 4
D. 1 2 4 3
Match each item in Column I with one item in Column II and chose your answer from the codes given below:
Column I Column II
(anibiotic) (effect)
I. Tetracycline 1. inhibits binding of amino acyl tRNA to ribosome
II. Streptomycin 2. inhibits initiation of translation
III. Chloramphenicol 3. inhibits peptidyl transferase
IV. Erythromycin 4. inhbits transloaction of mRNA along ribosome
Codes:
I II III IV
A. 1 2 3 4
B. 2 1 4 3
C. 2 1 3 4
D. 1 2 4 3
Which of the following cannot be inferred from the information given in the following diagram?
1. | The DNA from the crime scene matches that of individual B |
2. | VNTRs are hypervariable |
3. | The larger fragments remain near the point of introduction in the gel electrophoresis |
4. | The smaller chromosomes in the human genome have smaller repeats of VNTR |
Consider the following diagram showing the working of the lac operon in E.coli in the presence of an inducer and choose the correct statement from the ones given below:
1. | A is the inducer and can be either lactose or cAMP. |
2. | B is the enzyme that will metabolize glucose, the preferred energy source. |
3. | Some amount of C will be present in the cell even if lactose is absent. |
4. | The absence of D will stop lactose from entering the cell. |
Study the diagram given below and choose the correct information that can be deduced:
1. | The core RNA polymerase is capable of catalyzing elongation only. |
2. | Sigma factor and Rho factor are needed for the termination of transcription. |
3. | DNA Helicase opens the strand of the DNA. |
4. | Both strands of DNA are transcribed by the same RNA polymerase. |
Consider the transcription unit given in the following diagram and choose the correct statements:
I: | The promoter on the template is situated upstream and 5’ to the structural gene. |
II: | It is the presence of the structural gene that defines the template strand. |
III: | The coding strand does not code for anything and is displaced during transcription. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II and III |
A piece of nucleic acid used to find a gene, by forming a hybrid with it, is called a
1. Probe
2. Vector
3. Restriction sequence
4. Retrovirus
Which of the following was presented as evidence in favor of “the RNA world” hypothesis?
1. The fact that DNA can encode genetic information
2. The fact that enzymes, made of protein, can catalyze biological reactions
3. The discovery that some enzymes are composed of RNA rather than protein
4. The discovery of new life forms that encode their genetic information in RNA rather than DNA
The wobble effect is the:
1. Lack of precision with regard to the third base in the codon and anticodon
2. Instability of the DNA molecule when unwound
3. Instability of pairing when a purine pairs with another purine
4. Undulating movements of mRNA