Biotechnology: PCR, gel electrophoresis and genetic engineering
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Read this first
Model PCR card (model data)
item value start 5 pieces each cycle doubles the pieces goal more than 1000 pieces Ari starts a model PCR with 5 pieces. Each cycle doubles the pieces. After how many cycles does the count first pass 1,000?
- 7 cycles
- 498 cycles
- 8 cycles
- 200 cycles
Bo finds 192 pieces in a model PCR tube after 6 cycles. Each cycle doubled the pieces. How many pieces were in the tube at the start?
- 180 pieces
- 3 pieces
- 96 pieces
- 32 pieces
Each cycle doubles the pieces. Esme runs two model PCR tubes. Which tube has more pieces at the end, and by how many?
- Tube P, by 87 pieces
- Tube P, by 1,500 pieces
- Tube Q, by 320 pieces
- Tube P, by 320 pieces
not to scale; model data. Lane 3, one band: 300 bp. Lane 4, one band: 1200 bp. Jun runs PCR on a long piece of model plant DNA and loads the main product in one lane. Which lane is it, and why?
- Lane 1, because PCR copies the whole 5000 bp piece
- Lane 2, because PCR copies the region between the primers
- Lane 3, because each cycle halves the length of the product
- Lane 4, because each cycle doubles the length of the product
Model gel (not to scale; model data). Lane 1 holds the 1000 bp piece before cutting. Kira cuts a 1000 bp piece of DNA once with a restriction enzyme. Which lane shows the two pieces, and what happened in the run?
- Lane 3, toward the positive end, with the 500 bp piece farther
- Lane 2, toward the positive end, with the 600 bp piece farther
- Lane 2, toward the positive end, with the 400 bp piece farther
- Lane 2, toward the negative end, with the 400 bp piece farther
Use this
Model gel (not to scale; model data). Lane 1 is model corn plant DNA and lane 2 is model soil bacterium DNA, both cut by the same enzyme.
Luz compares the two lanes of this model gel. Which statement matches the gel?
- The 700 bp bands match, and the 1200 bp band moved farthest of all
- No bands match, because the samples come from different kinds of organisms
- The 700 bp bands match, and the 200 bp band moved farthest of all
- The 700 bp bands match, and the pieces moved toward the negative (−) end
Notebook on gene cloning (model data)
line what it says 1 A restriction enzyme cuts DNA at a specific sequence 2 Cutting the plasmid and the gene with the same enzyme leaves matching sticky ends 3 DNA ligase cuts the plasmid so the gene can fit 4 Bacteria copy the plasmid as they divide Milo checks a classmate's notebook on putting a gene into a plasmid. Exactly one line is wrong. Which line, and why?
- Line 3, because DNA ligase joins DNA and does not cut it
- Line 2, because sticky ends form with different enzymes, not the same one
- Line 1, because a restriction enzyme joins DNA pieces
- Line 4, because a plasmid cannot be copied inside bacteria
Use this
Notebook on PCR and gels (model data), 4 rows. Columns: line, what it says. 1, PCR copies the region between the two primers. 2, Each cycle doubles the target pieces, so 3 cycles turn 1 piece into 8. 3, In a gel, smaller pieces travel farther from the wells. 4, DNA pieces move toward the negative end of the gel.
Pia checks a classmate's notebook on PCR and gels. Exactly one line is wrong. Which line, and why?
- Line 2, because each cycle adds two pieces, so 3 cycles give 7 pieces
- Line 4, because negatively charged DNA moves toward the positive end
- Line 3, because larger pieces travel farther from the wells in a gel
- Line 1, because PCR makes copies of the whole genome in the cell
Model PCR card (model data)
item value start 1 piece each cycle doubles the pieces cycles 10 Tala predicts the pieces in a model PCR tube after 10 cycles. Which claim and reason are correct?
- 100 pieces, because each cycle multiplies the number by 10
- 1,024 pieces, because each cycle doubles the number
- 21 pieces, because each cycle adds two pieces
- 10 pieces, because each cycle adds one piece
Two crops card (model data)
crop what was added what it makes Bt corn a gene from Bacillus thuringiensis a protein that protects it from some insect pests golden rice a combination of added genes provitamin A in the endosperm Zee compares Bt corn and golden rice. Which claim and reason are correct?
- Each crop carries added genes, because restriction enzymes join them to the plant's DNA
- Bt corn carries added genes but golden rice does not, because rice cannot take up recombinant DNA
- Each crop carries added genes, because engineering puts recombinant DNA into the organism
- Each crop has a replaced genome, because engineering swaps out the plant's genes