Transcription: from DNA to messenger RNA

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Use this

   Model template (not to scale). The mRNA is built base by base under the template; its nine bases are the answer.

2. 1.

   Ari writes the mRNA that RNA polymerase builds from this template. Which mRNA is correct?

   • AUGCGAACU
   • ATGCGAACT
   • UCAAGCGUA
   • UACGCUUGA
3. 2.

   Model strands (not to scale). The blanks are bases 2, 4 and 6 of the mRNA. Bo fills three blanks in the mRNA built from this template. Which letters go in the blanks, in order?

   • G, A, U
   • U, A, G
   • T, A, G
   • A, U, C
4. 3.

   Model gene (not to scale). RNA polymerase builds mRNA from the template strand of Esme’s model gene. Which mRNA is built?

   • ATGAACCTA
   • AUGAACCUA
   • UACUUGGAU
   • TACTTGGAT
5. 4.

   A gene’s coding strand is shown. Jun writes the mRNA built from its template strand. Which mRNA is correct?

   • AUGGCUUAC
   • UACCGAAUG
   • ATGGCTTAC
   • CAUUCGGUA
6. 5.

   (not to scale). Kira reads a coding strand and writes the mRNA built from the gene. How many U bases will the mRNA have?

   • 6 U bases
   • 4 U bases
   • 2 U bases
   • 0 U bases
7. 6.

   Luz compares the three strands of a model gene. Which statement about the mRNA is true?

   • It is built on both DNA strands at the same time
   • It matches the coding strand, with U for T
   • It has the same letters as the template strand
   • It pairs with the coding strand, base for base
8. 7.

   built from the gene. Noah finds the mRNA that a polymerase built from this gene. Which strand was the template, and why?

   • Neither strand, because mRNA is built without a template
   • Strand 1, because the mRNA has the same letters as strand 1
   • Strand 2, because the mRNA bases pair with strand 2
   • Both strands, because the polymerase reads the whole double helix
9. 8.

   Model template (not to scale). Pia reads a template strand. Which DNA strand has the same sequence as its mRNA, with T where the mRNA has U?

   • 5′ ATGCCT 3′
   • 5′ AUGCCU 3′
   • 5′ TCCGTA 3′
   • 5′ TACGGA 3′

10. Transcription steps, not in order (model data)

    step	what happens
    W	RNA polymerase builds the mRNA by pairing bases with the template
    X	RNA polymerase binds at the promoter
    Y	At a termination signal the polymerase leaves the DNA and frees the mRNA
    Z	The DNA partly unwinds

11. 9.

    Ren puts four steps of transcription in order. Which order is right?

    • W, X, Z, Y
    • X, Z, W, Y
    • X, W, Z, Y
    • Z, X, W, Y

12. Use this

    Route of the mRNA in a plant cell, not in order (model data), 4 rows. Columns: step, what happens. W, The finished mRNA leaves the nucleus through a nuclear pore. X, RNA polymerase builds the pre-mRNA in the nucleus. Y, The pre-mRNA gets a cap and a tail, and its introns are cut out. Z, A ribosome in the cytoplasm reads the mRNA.

13. 10.

    Tala puts four steps in order for the mRNA of a plant cell. Which order is right?

    • W, X, Y, Z
    • X, Y, W, Z
    • X, W, Y, Z
    • Y, X, W, Z