DNA Structure
What are the four nitrogen bases in DNA?
A, T, C, G
What is
Chargaff's rule?
A pairs with T and C pairs with G
Where is the DNA located in eukaryotic cells?
Inside the nucleus
What did smashing the strawberries accomplish?
It broke the cell walls
What is an independent variable?
The thing you change in an experiment
What three parts make up a nucleotide?
sugar, phosphate, base
If A=30%, what is T?
30%
What is the function of the nucleus?
To protect DNA and regulate gene expression
Why was dish soap added?
To dissolve membranes
What is a dependent variable?
The thing you measure in and experiment as a result of the thing you changed.
What is the shape of DNA called?
Double helix
If C=18%, what is G?
18%
What is the cell membrane made of?
Phospholipid bilayer
What role did salt play in the extraction?
It helped DNA clump by neutralizing charges
Why are control groups important?
They allow comparison to show the effect of the variable
How does complementary base pairing allow DNA to replicate accurately?
Each base pairs with a specific partner (A-T, C-G)
If A=22%, what percentage of the DNA is G?
28%
Why is DNA tightly packaged inside the nucleus?
To protect it and organize it efficiently.
Why did cold alcohol make the DNA visible?
DNA is not soluble in cold alcohol and precipitates out
How does increasing sample size improve reliability(ie. testing a large group of people versus a small group)?
It reduces random variation in the results.
Why does the double helix structure help DNA store large amounts of information?
Its twisting allows long sequences of base pairs to be organized compactly.
Why must base pairing follow specific rules instead of random pairing?
To ensure proper shape and replication accuracy
What might happen if DNA were not protected inside the nucleus?
It could get damaged and lead to malfunction or mutations
If we skipped one step, which would most disrupt the experiment and why?
Skipping soap would leave membranes intact, blocking DNA release.
Why must scientists explain their reasoning, not just state their results?
So others understand how evidence supports the conclusion