cDNA synthesis and Gene Libraries

What is the correct order of steps and the corresponding enzymes required for the synthesis of cDNA from mRNA?

• 1. RNA degradation by RNase HI
         2. First cDNA strand synthesis by DNA polymerase I
         3. Second cDNA strand synthesis by Reverse Transcriptase

• 1. First cDNA strand synthesis by Reverse Transcriptase
         2. Partial RNA degradation by RNase HI
         3. Second cDNA strand synthesis by DNA polymerase I

• 1. Partial RNA degradation by RNase HI
         2. First cDNA strand synthesis by DNA polymerase I
         3. Second cDNA strand synthesis by Reverse Transcriptase

• 1. First cDNA strand synthesis by Reverse Transcriptase
         2. Complete RNA degradation by RNase HI
         3. Second cDNA strand synthesis by DNA polymerase I

What is the main difference between cDNA and genomic DNA?

• cDNA contains regulatory elements

• cDNA contains both exons and introns

• cDNA includes only the sequences that are expressed as mRNA, representing active genes

• cDNA is easier to sequence

What is the role of RNase HI during cDNA synthesis?

• It synthesizes the second cDNA strand

• It degrades the mRNA template completely

• It partially degrades the RNA template, leaving fragments as primers

• It ligates the cDNA into the vector

What are the correct steps involved in the construction of a genomic library?

• 1. Cloning of Genomic DNA into vectors
         2. Isolation of Genomic DNA
         3. Fragmentation of Genomic DNA
         4. Transformation into host cells

• 1. Transformation into host cells
         2. Fragmentation of Genomic DNA
         3. Isolation of Genomic DNA
         4. Cloning into vectors

• 1. Fragmentation of Genomic DNA
         2. Isolation of Genomic DNA
         3. Cloning into vectors
         4. Transformation into host cells

• 1. Isolation of Genomic DNA
         2. Fragmentation of Genomic DNA
         3. Cloning of DNA into vectors
         4. Transformation into host cells

Which of the following best describes a genomic library?

• A collection of only expressed genes from an organism.

• A collection of all RNA molecules from an organism.

• A complete collection of cloned DNA fragments representing the entire genome of an organism.

• A collection of cloned proteins from an organism.

What is the primary purpose of fragmenting genomic DNA during the construction of a genomic library?

• To remove non-coding regions from the DNA.

• To create smaller fragments that can be cloned into vectors.

• To separate mRNA from the DNA.

• To eliminate introns from the DNA fragments.

What does a cDNA library represent?

• A collection of cDNA molecules derived from mRNA, representing only expressed genes.

• A collection of proteins synthesized by an organism.

• The entire genome of an organism, including non-coding regions.

• The complete set of ribosomal RNA in a cell.

What is the correct sequence of steps for constructing a cDNA library?

• • cDNA Synthesis

  • Transformation

  • mRNA Isolation

  • cDNA Cloning

• • Transformation

  • cDNA Synthesis

  • mRNA Isolation

  • cDNA Cloning

• • cDNA Cloning

  • mRNA Isolation

  • cDNA Synthesis

  • Transformation

• • mRNA Isolation

  • cDNA Synthesis

  • cDNA Cloning

  • Transformation

In the process of creating a cDNA library, what is the purpose of using oligo-dT-coated resins?

• To fragment genomic DNA.

• To amplify cDNA.

• To isolate mRNA

• To degrade non-coding RNA.

Which of the following is a key difference between genomic libraries and cDNA libraries?

• Genomic libraries represent expressed genes in different cells depending on physiological conditions, while cDNA libraries contain all the genes of an organism, including regulatory sequences.

• cDNA libraries reflect the gene expression levels specific to a cell's state and physiological conditions, while genomic libraries contain all the genes and regulatory sequences, regardless of expression.

• In genomic libraries, gene expression varies based on cell type and conditions, while cDNA libraries represent the entire genome equally.

• Genomic libraries are constructed from mRNA transcripts, while cDNA libraries represent all genes, including non-coding regions like introns and promoters.