Precision will be reduced, but yield will be increased

Optimisation of a PCR reaction is often a compromise between the competing demands for precision, efficiency and yield. Although the specific effects may vary, generally, increasing the annealing temperature will increase non-specific primer binding and reduce precision. Increasing the length of the elongation phase will reduce the proportion of incomplete newly-synthesised strands and therefore increase yield. In this case, the potential effect on efficiency is unclear. Increasing the elongation phase would increase the reaction time, but the time taken to ramp down to a lower annealing temperature would be reduced.

Arrange in the order of their increasing capacity:

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#Question id: 12909

#SCPH28 | Zoology

According to the diagram, arrange the steps in correct order: 

1. DNA is then digested by the Cas9 nuclease at specific points on both DNA strands. 

2. Homologous recombination to repair the break and incorporate the new DNA sequence then follows. 

3.The nuclease Cas9 is targeted to DNA by a guide RNA consisting of a specific 20 nucleotide spacer/targeting sequence (crRNA).

 4. That identifies the DNA to be modified, linked to a trans-activating (tracrRNA) sequence necessary for the recruitment and stability of Cas9 nuclease.

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#Question id: 12910

#SCPH01 Biochemistry

Match the following:

A. RNA analysis               i. Sexing or cell mutation sites               a. Expressed Sequence tag

B. Forensic science           ii. mRNA analysis                                     b.  Analysis of DNA from blood

C. Gene discovery              iii. DNA profiling                                       c. Active latent viral infections

D. Single-cell analysis     iv.  RT–PCR                                             d. Sex determination of unborn

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#Question id: 12910

#SCPH06 I Botany

Match the following:

A. RNA analysis               i. Sexing or cell mutation sites               a. Expressed Sequence tag

B. Forensic science           ii. mRNA analysis                                     b.  Analysis of DNA from blood

C. Gene discovery              iii. DNA profiling                                       c. Active latent viral infections

D. Single-cell analysis     iv.  RT–PCR                                             d. Sex determination of unborn

TLS Online TPP Program

#Question id: 12910

#SCPH28 | Zoology

Match the following:

A. RNA analysis               i. Sexing or cell mutation sites               a. Expressed Sequence tag

B. Forensic science           ii. mRNA analysis                                     b.  Analysis of DNA from blood

C. Gene discovery              iii. DNA profiling                                       c. Active latent viral infections

D. Single-cell analysis     iv.  RT–PCR                                             d. Sex determination of unborn

TLS Online TPP Program

#Question id: 12911

#SCPH01 Biochemistry

Match the following:

A. DNA polymerases              i. Alkaline phosphatase        a.RNA-dependent DNA polymerase, used in cDNA synthesis

B. Reverse transcriptase        ii. T4 DNA ligase                    b. Thermostable DNA polymerase used in PCR

C. Ligases                                 iii.  AMV-RT                            c. Removes 5′-phosphates from DNA and RNA

D. Phosphatases                     iv. Taq DNA pol                      d. Links 5′-phosphate and 3′-hydroxyl ends via phosphodiester bond

TLS Online TPP Program

#Question id: 12911

#I Life Science/ Life Sciences Group – I-V

Match the following:

A. DNA polymerases              i. Alkaline phosphatase        a.RNA-dependent DNA polymerase, used in cDNA synthesis

B. Reverse transcriptase        ii. T4 DNA ligase                    b. Thermostable DNA polymerase used in PCR

C. Ligases                                 iii.  AMV-RT                            c. Removes 5′-phosphates from DNA and RNA

D. Phosphatases                     iv. Taq DNA pol                      d. Links 5′-phosphate and 3′-hydroxyl ends via phosphodiester bond