The structure of DNA
Dna contains four kinds of nitrogenous bases:
Adenine, Thymine, Guanine, Cytosine
Is dna replication always a fool proof process?
No, damaged areas are still able to be replicated
Does DNA replication take place in the same direction along both strands of the DNA molecule that is being replicated?
No. DNA replication proceeds in opposite directions between replication forks.
Why is the pairing of bases during replication essential for the transmission of inherited traits from parent to offspring?
Offspring will always get the same sequence of bases their parents had.
A kind of virus that infects bacteria
bacteriophage
Hershey and Chase studied a ________ that was composed of a DNA core and a protein coat
bacteriophage
In DNA, the fit between thymine and adenine and the fit between cytosine and guanine
base pairing
The double helix model explains chargaffs rule of ____
base pairing
James Watson and Francis Crick
built a model that explained the structure of DNA
The nucleotides in dna are joined by _____ bonds.
covalent
Why are the strands of a DNA molecule said to be complementary?
each strand can be used to make the other strand
Amount of DNA in prokaryotes
less than eukaryotes
In DNA, _________ can be joined in any order.
nucleotides
The building blocks of dna are
nucleotides
Location of dna in eukaryotes
nucleus
In eukaryotic cells, ____ can begin at dozens or even hundreds of places on the dna molecule
replication
The DNA molecule separates into two strands during __________
replication
The process that copies a DNA molecule
replication
What enzyme makes it less likely that DNA will be lost from telomeres during replication?
telomerase
The tip of a chromosome
telomere
The process that can change a harmless bacterial strain into disease causing strain
transformation
Why did Hershey and chase specifically choose the sulfur and phosphorus labels?
To differentiate between dna and protein
Why was the bacteriophage a quality model to use in an experiment designed to answer the question " is the genetic material protein or dna"?
Bacteriophages are made of only two components, a protein capsule and dna. They attach to the surface of a bacteria cell, inject there dna into the cell but very little of their protein
The center of the dna strands exhibits _____
Base pairing
Location of dna in prokaryotes
Cytoplasm in the nucleotide
An enzyme that joins individual nucleotides to produce a new strand of dna
DNA polymerase
The principle enzyme involved in dna replication is ____
DNA polymerase
Nucleotides in dna are made of three basic components: a sugar called_____, a ______, and a nitrogenous _____.
Deoxyribose, phosphate, base
How does this enzyme work?
Dna May be lost from the tips of chromosomes
Starting Points for Replication (Eukaryotes)
Dna molecule
The enzymes that proof reads each new dna strand so that each molecule is a near-perfect copy of the original is ______
Dna polymerase
What enzymes join individual nucleotides to produce the new strand of dna
Dna polymerase
How does DNA store information?
Each strand of double helix carries a sequence of bases arranged by letters
If the base sequence on a separated DNA strand is CGTAGG, what will the base sequence on its complementary strand be?
GCATCC
Rosalind franklin
Her X-ray diffraction studies revealed the double-helix structure of DNA
What was the independent variable in this experiment?
Radioactivity and phages that were grown
Erwin Chargaff
Showed that the percentages of adenine and thymine are almost always equal in DNA. The percentages of guanine and cytosine are also almost equal.
Starting points for replication in prokaryotes
Single point
Each time a chromosome is replicated some dna may be low from the tip of the chromosome or ______
Telomere
How does dna copy information
The base pairs can be copied when hydrogen bonds break
What was the dependent variable in this experiment?
The part of the virus that was injected
How does DNA transmit information?
The sequence of base pairs is copied so genetic info can be duplicated unchanged
What is the first step in eukaryotic dna replication?
The strands of the double helix separate, or unzip
Griffiths experiment showed that some chemical compound in cells must be responsible for bacterial____
Transformation
Amount of DNA in eukaryotes
Up to 1000X more than prokaryotes.
What was the purpose of the blender in the experiment
Whether or not bacteria is radioactive in the experiment
The physical shape of dna looks like an
X and is double sided
What is a replication fork?
a Y-shaped region where the parental strands of DNA are being unwound