How Scientists Copy DNA
The basic workflow
Overview
To clone DNA, scientists usually place a gene into a DNA carrier called a vector. The vector enters a living cell, and the cell makes many copies of the vector as it grows and divides.
Typical cloning steps
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Step 1: Choose the DNA fragment or gene you want to copy.
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Step 2: Put the DNA into a vector.
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Step 3: Move the vector into a host cell.
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Step 4: Let the cell copy the vector as it grows.
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Step 5: Identify cells that carry the correct DNA.
Big idea
Scientists often use cells as tiny DNA-copying machines.
Why cells help
Cells naturally copy their DNA before dividing. If a vector is designed correctly, the cell will also copy the inserted gene along with the vector DNA.
Cloning vs. copying by hand
By hand
- Slow and error-prone
- Not practical for tiny DNA pieces
Using cells
- Fast once set up
- Can make many copies at once
What does a host cell do in DNA cloning?
The host cell replicates the vector, which copies the inserted DNA too.
Correct answer: Copies the vector and inserted DNA
Why do scientists use a vector?
Vectors act as transport vehicles for DNA.
Correct answer: A vector carries the DNA fragment into a host cell and helps it be copied.
Which step usually comes first?
The cloning process starts by selecting the DNA you want to copy.
Correct answer: Choose the DNA fragment