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9th grade Biotechnology: PCR, gel electrophoresis and genetic engineering worksheet

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Biotechnology: PCR, gel electrophoresis and genetic engineering

Grade 9 Science Worksheet

NameDate

Circle the best answer.

  1. Read this first

    Model PCR card (model data)

    itemvalue
    start3 pieces
    each cycledoubles the pieces
    cycles5

  2. Ari starts a model PCR with 3 pieces of the target region. Each cycle doubles the pieces. How many pieces are there after 5 cycles?

    • 48 pieces
    • 96 pieces
    • 13 pieces
    • 15 pieces

  3. Bo starts a model PCR with 1 piece. Each cycle doubles the pieces. What is the fewest cycles that pass 1,000 pieces?

    • 100 cycles
    • 500 cycles
    • 10 cycles
    • 9 cycles

  4. Jun reads a model of Taq polymerase extending a primer. What is the whole new strand, written 5′ to 3′?

    • ATGCGATT
    • ATGCAATC
    • ATGCCTAA
    • ATGCCUAA

  5. Model strands (not to scale). In each cycle, every single strand gets a new partner strand built by Taq polymerase. Kira follows a model PCR that starts with one double strand. Each cycle gives every single strand a new partner. How many single strands are there after 4 cycles?

    • 32 strands
    • 24 strands
    • 16 strands
    • 64 strands

  6. Model strands (not to scale). Luz reads a model of one PCR step. A primer is paired with the template. Which statement about Taq polymerase is correct?

    • Taq cuts the template after the primer and keeps the first part
    • Taq builds GCTAATGG by adding bases to the primer
    • Taq builds a copy of the whole genome starting from the primer
    • Taq builds GCTATACC by copying the template letters

  7. Model gel (not to scale; model data). Wells at the top, next to the negative (-) end. Milo reads a model gel. Lane 1 has one band between the 750 bp and 500 bp ladder bands. Which size fits that band best?

    • 900 bp
    • 300 bp
    • 600 bp
    • 1200 bp

  8. “not to scale; model data” Noah reads a model gel with four lanes after the run. Which lane has the band that moved farthest from the wells?

    • Lane 1, because it holds the largest piece, 900 bp
    • Lane 3, because it holds the smallest piece, 120 bp
    • Lane 4, because its band lines up with a ladder band
    • Lane 2, because it has the most bands

  9. (not to scale; model data). Pia compares model DNA from three soil bacteria samples, each cut by the same enzyme. Which two samples show the same band pattern?

    • Q and R, because both have two bands
    • P and Q, because both have a band at 800 bp
    • P, Q and R, because three samples have a band at 800 bp
    • P and R, because both have bands at 800 bp and 300 bp

  10. Ren reads four steps for putting a gene into a plasmid. Which order is correct?

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

  11. Rice grain card (model data)

    factdetail
    golden ricea combination of added genes lets the endosperm make provitamin A (beta-carotene)
    rice grainthe endosperm is the edible part of the grain

  12. Zee reads a card about golden rice, a rice engineered to make provitamin A. Which statement does the card support?

    • Provitamin A is sprayed onto the grain after the plant is harvested
    • Added genes let the endosperm, the edible part, make provitamin A
    • The roots of the rice plant make provitamin A and send it to the grain
    • The genes of the rice plant were replaced, so the grain makes provitamin A
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9th grade Biotechnology: PCR, gel electrophoresis and genetic engineering worksheet – printable
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About this worksheet

Biotechnology: PCR, gel electrophoresis and genetic engineering. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can name the three steps of a PCR cycle from what happens in each: the strands pull apart at a high temperature (denature), primers join the single strands at a low temperature (anneal), and Taq polymerase builds new strands from the primers at a medium temperature (extend).
  • I can say why Taq polymerase is used: it comes from a heat-stable bacterium and keeps working after the hot step.
  • I can say that PCR copies the region between the two primers, and not the whole genome.
  • I can count a model PCR: each cycle doubles the pieces, so n cycles multiply the start by 2^n. I can find the count after n cycles, the cycles needed to pass a goal, and the start from the end.
  • I can tell doubling from adding two each cycle, and I can count single strands as well as double strands.
  • I can write the new strand that Taq builds from a primer on a template, by pairing A with T and C with G.

Standard: supports HS-LS3-1

Words to know

PCR: A way to make many copies of one region of DNA in a tube

target region: The stretch of DNA between the two primers that PCR copies

primer: A short piece of DNA that pairs with one end of the target region

denature: Heat the DNA until its two strands pull apart

anneal: Cool the tube so the primers join the single strands

extend: Taq polymerase builds a new strand from each primer

Taq polymerase: A heat-stable DNA polymerase from a heat-tolerant bacterium

cycle: One round of denature, anneal and extend

Common mistakes

Your child added two pieces each cycle. PCR doubles the pieces in every cycle, so the count grows 1, 2, 4, 8. Ask your child what the count does in each cycle.

Your child thought larger DNA pieces travel farther in a gel. Smaller pieces move through the gel faster and end up farther from the wells. Ask your child which piece travels farthest.

Your child said DNA moves toward the negative end of a gel. DNA is negatively charged, so it moves toward the positive end. Ask your child which end the wells are next to.

Questions parents ask

What is the most common mistake with biotechnology: pcr, gel electrophoresis and genetic engineering?

Your child added two pieces each cycle. PCR doubles the pieces in every cycle, so the count grows 1, 2, 4, 8. Ask your child what the count does in each cycle.

Are these 9th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

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