Scientists
Which scientist's X-ray diffraction photo helped reveal the structure of DNA?
Rosalind Frankllin
The structure of DNA is often referred to as a _______ _______ _____.
Double stranded helix
In complementary base pairing, which base pairs with cytosine?
Guanine
During which phase of cell division does DNA replication occur?
S (synthesis) phase
What enzyme works to seal up Okazaki fragments that occur on the lagging strand during replication?
Ligase
Who created the first 3D helical model of DNA?
Watson and Crick
The strands (backbone) of the DNA molecule are made of what two components?
Sugar and phosphate
In complementary base pairing, which base pairs with thymine?
Adenine
Helicase is the enzyme that unzips the DNA strands for replication. What does this produce in the DNA molecule?
Replication forks
Which enzyme acts as a proofreader in DNA replication because it only adds a new nucleotide if the preceding one was correctly paired?
DNA polymerase
Chargaff's First Rule states that adenine pairs with thymine and cytosine pairs with guanine. What is another name for this idea?
Complementary base pairing
Which nitrogenous bases are purines? Which nitrogenous bases are pyrimidines?
Adenine and guanine. Thymine and cytosine.
If we have a DNA molecule containing 50 bases and 9 of them are guanine, how many adenine, thymine, and cytosine must there be?
16 adenine, 16 thymine, 9 cytosine
Which enzyme uses complementary base pairing to add nucleotides to the new strand of DNA?
DNA polymerase
What is the sequence for the compaction of DNA in the nucleus?
Chromatin -> chromosome -> sister chromatids
What do the letters DNA stand for?
Deoxyribonucleic Acid
How many phosphates are present in one nucleotide?
One
Which scientist discovered that adenine pairs with thymine and guanine pairs with cytosine?
Erwin Chargaff
In which direction does DNA polymerase work? What forms on the strand that DNA polymerase does not work on?
5' to 3'. Okazaki fragments.
Why does DNA have to be compacted to fit into the nucleus?
DNA is a large nucleic acid.
Why is it important that we understand the structure of DNA and how it replicates?
(Answers may vary.) Understanding the structure and replication process of DNA allows us to understand how traits are passed down and how mutations arise and what affect they have on an organism.
How do the nucleotides in DNA differ from an ATP molecule?
DNA nucleotides have only one phosphate, while ATP has three phosphate molecules.
The two strands of DNA run opposite each other. How else would we describe this?
(Answers may vary). DNA is anti-parallel. OR One strand runs from 5' to 3' while the other strand runs from 3' to 5'.
DNA replication is semi-conservative. What does this mean in relation to the DNA strands?
(Answers may vary.) One DNA strand is new, while the other is the old strand from the original DNA molecule.
_______ are repetitive sequences at the ends of chromosomes that help prevent degradation of information during DNA replication.
Telomeres