How To Get a Gene

Overview

To obtain a gene of interest, there are three main methods: isolating it from the chromosome, chemically synthesizing it, or creating it from mRNA. Genes can be isolated from chromosomes by using restriction endonucleases to cut the DNA at specific sites. Another approach is to synthesize the gene in the laboratory from messenger RNA using reverse transcriptase, resulting in complementary DNA (cDNA).

Questions and Answers

  1. How can genes be obtained from chromosomes?

    Genes can be isolated from chromosomes by cutting them at specific sites using restriction endonucleases.

  2. What is the process of synthesizing genes in the laboratory?

    Genes can also be synthesized in the laboratory from messenger RNA using reverse transcriptase to create complementary DNA (cDNA).

  3. What are restriction endonucleases and how are they used in obtaining genes?

    Restriction endonucleases are enzymes that cut DNA at specific sites, allowing for the isolation of genes from chromosomes.

  4. Explain the role of molecular scissors in gene isolation.

    Molecular scissors, such as restriction endonucleases, are used to cut DNA at specific sites to obtain genes of interest.

  5. What is the significance of complementary DNA (cDNA) in gene isolation?

    cDNA is synthesized from messenger RNA and serves as a template for gene cloning and manipulation.

Multiple-Choice Questions

  1. What is the process of isolating a gene from the chromosome called?

    a) Transcription
    b) Isolation
    c) Translation
    d) Replication
    Answer: b) Isolation

  2. Which enzyme is used to cut the chromosomes on the flanking sites of the gene?

    a) DNA polymerase
    b) Ligase
    c) Restriction endonuclease
    d) Helicase
    Answer: c) Restriction endonuclease

  3. What is the DNA molecule called when synthesized from messenger RNA using reverse transcriptase?

    a) mRNA
    b) tRNA
    c) cDNA
    d) rRNA
    Answer: c) cDNA

  4. Which natural enzymes of bacteria are used for cutting viral DNA?

    a) Ligase
    b) Helicase
    c) Polymerase
    d) Restriction endonucleases
    Answer: d) Restriction endonucleases

  5. What is the term for the specific sequences of nucleotides where restriction enzymes cut DNA?

    a) Palindromic sequences
    b) Complementary sequences
    c) Symmetrical sequences
    d) Reverse sequences
    Answer: a) Palindromic sequences