Question

a person cant see a single cotton thread from far away, but 1,000 woven cotton threads would be much more visible. how does this relate to the dna we extracted in the lab?
to see dna without a microscope, many strands must be clumped together.
to see dna without a microscope, clumped strands must first be pulled apart.
individual dna strands can always be seen without a microscope.
to see dna without a microscope, the dna must be woven together with cotton.

Explanation:

The analogy of a single cotton thread being invisible from far away but 1000 woven threads being visible is used. DNA is very small. Just like the threads, a single DNA strand is too small to see without a microscope. But when many DNA strands are clumped together (like the woven threads), they can be seen without a microscope. The other options are incorrect:

• Option 2: Clumped strands don't need to be pulled apart to be seen without a microscope (the analogy is about clumping for visibility).
• Option 3: Individual DNA strands can't be seen without a microscope (they are too small).
• Option 4: There's no need to weave DNA with cotton; the analogy is about the concept of clumping multiple small things (threads/DNA strands) for visibility.

Answer:

To see DNA without a microscope, many strands must be clumped together.