Bio Exam 4 Chapter 11

michelleburkee2's version from 2015-11-16 05:28

Section 1

Question Answer
heritable information is carried in discrete units calledgenes
what are genes made out of?DNA
what are chromosomes made out of?DNA and protein
How did Griffith reveal the link between genes and bacteria?He first injected one mouse with a R-strain and another mouse with the heat killed S-strain and noticed they were not affected. The mouse injected with the regular S-strain died. When he injected one mouse with both the heat killed S-strain and the R-strain the mouse died. this revealed that the R-strain inherited bad traits from the heat killed S-strain that caused the mouse to die. A substance from the heat-killed S-strain TRANSFORMED the harmless R-strain into a deadly S-strain.
how was DNA found to be the heredity material?transformation cannot occur without DNA therefore DNA is the heredity material.
can transformation happen in the abscense of protein?yes
what provides us with the answer to how inheritance works?the structure of DNA
do we know how inheritance works just because we know it is the molecule of inheritance?no
what kind of sturcture does DNA have?3-dimensional double helix structure
DNA is composed of:four nucleotides
what is each nucleotide composed of? (3 things)a phosphate group, a deoxyribose sugar, and 1 of the four nitrogen containing bases (Thymine, Cytosine, Guanine, and Adenine)
the shape of adenine and guanine are _____ and the shape of thymine and cytosine are ______adenine and guanine are fat and cytosine and thymine are thin
what is Chargaff's rule?the amount of Adenine=the amount of Thymine; the amount of Guanine=the amount of Cytosine
how did scientist discover the shape of DNA?through X-ray diffraction

Section 2

Question Answer
what determines many inheritable traits?genes
can trasnformation happen in the abscense of RNA?yes
can transformation happen in the absense of DNA?no. Therefore it was found to be the heredity material.
describe how Griffith's expiriment worked once we knew that DNA was the heredity material.heating the S-strain killed them but did not kill the DNA. When the mouse was injected with both heated S-strain and R-strain the dangerous DNA from the S-strain transformed the R-strain into an S-strain cell.
what are the four different nitrogen containing bases?guanine, cytosine, thymine, and adenine
what is the monomer of DNA?nucleotides
What type of bonds connect the nucleotides in DNA?covalent bonds
G and C make how many hydrogen bonds?3
A and T make how many hydrogen bonds?2
why is the amount of Adenine and Thymine always the same?because they can only pair with eachother (same with for Cytosine and Guanine)

Section 3

Question Answer
what shape is DNA?a double helix
a molecule of DNA is ______ and _____ with a diameter of long and thin with a dimater of 2 nanometers
DNA has _______ subunitsrepeating
______ are on the outside of the helixphosphates
DNA has _____ nucleotide stand(s)two
Each strand of DNA is a polymer consisting of nucleotides connected together by covalent bonds
deoxyribose sugar and phosphate portions make up thesugar-phosphate backbone
the strands of DNA are directional (the ends are different)
The ends of the DNA:5' prime phosphate on one end and a 3' OH sugar on the other end
always write sequences fromthe five prime to the three prime end (i.e. 5'-A-T-G-3')
where are the nucleotide bases on the nucleotide strand?pertruding out and points away from the sugar-phosphate backbone so they are available for hydrogen bonding
what holds the two DNA strands together?hydrogen bonding between complimentary base pairs
In DNA, each standfaces eachother and together they coil around to create a double helix
_______ are on the outside of the DOUBLE helixsugar phosphate backbones
in the double helix, the bases pertrude inward towards eachother
which is stronger and why: the bonds between G and C or the bonds between A and T?the bonds between G and C because they have 3 hydrogen bonds and A and T only have two.

Section 4

Question Answer
Where are the covalent bonds located in DNA?between the phosphate of one nucleotide to the sugar of the next
why do the bases pertrude out in the nucleotide strand?so they are available for hydrogen bonding
what type of bonds hold the base pairs together in a double helix?hydrogen bonds
what types of bonds hold the nucleotides together in each strand of DNA?covalent bonds
the two strands of DNA in the double helix are ______ (the set up)antiparrallel. This means one strand startes with the 5' phosphate and ends with the sugars 3' OH while the other one starts with the 3'OH and ends with the 5' phosphate
the pairs of strands of DNA are going in _______ directionopposite
bases that can pair up by hydrogen pairing are calledcomplimentary base pairs
Guanine can only pair withCytosine
Cytosine can only pair withGuanine
Adenine can only pair with Thymine
Thymine can only pair withAdenine
why does the diameter of DNA remain constant?because a big base always bonds with a small base

Section 5

Question Answer
what does it mean that the strands of DNA are antiparallel?the strands of DNA are lined up in opposite directions. The 5' phosphate->3' OH sugar strand pairs with 3'<-5' (5 pairs with 3)
can guanine pair with cytosine?yes
can cytosine pair with adenine?no
can adenine pair with thymine?*yes*
can thymine pair with guanine?*no*
why is a large base always paired with a small base?so the diameter of DNA stays constant
________ is a template to make a new copy of DNAeach strand of DNA
enzymes involved in DNA replicationDNA helicase and DNA polymerase
what enzyme pulls apart the parental DNA double helix at the hydrogen bonds between the complimentary base pairs?DNA helicase
What enzyme is responsible for synthesizing new strands of DNA?DNA polymerase

Section 6

Question Answer
Andenine and guanine arelarge
thymine and cytosine are small
a _____ base always is paired with a _____ base large base is always paired with a small base
cells reproduce bydividing in half
each daughter cell gets an ______ of the parent cell's informationexact copy
DNA replicationduplication or the parent cell's DNA
why is each strand of DNA a template to create a new copy of DNA?because of the double helix structure and the rules of base pairing (A to T and C to G)
DNA replication makes _______ each with _______two DNA double helices, each with one origonal and one new strand
the ingredients for DNA replication (3 things)a parental DNA double helix, free nucleotides, and a variety of enzymes that unwind the parental DNA double helix and synthesize the new DNA strands
function of DNA helicasepull apart the parental DNA double helix at the hydrogen bonds between the complimentary base pairs
function of DNA polymerasehelps synthesize new strands of DNA (puts new DNA strands together). it pairs free nucleotides with their complimentary nucleotides on each seperated strand.
T/F every DNA strand has one replication bubblefalse. every DNA strand has several replication bubbles so they can replicate DNA fastly
the orgin where replication beginsthe replication bubble
what increases the size of the replication bubble? How?replication forks. They are on both sides of the replication bubble and move away from eachother

Section 7

Question Answer
DNA polymerase adds ___ to the _____ side of the DNA strandfree nucleotides to the 3' OH side of the DNA strand
DNA adds nucleotides according to base pairing rules
if a parental strand reads 5'-A-T-G-3' the new strand will read 3'-T-A-C-5'
you always read the DNA strand from ****5' to 3'
2 new DNA strads:one continuous and one discontinuous (short pieces). DNA ligase "fills the gaps"
function of DNA ligase"fills the gaps" on discontinuous DNA strand by forming nucleotide bonds between the short DNA pieces of the discontinuous strand so it becomes a normal continuous strand
nucleotides can only be added tothe free sugar end of the strand (so it goes from the 5 to 3 side) on the NEW strand
what does it mean that DNA replication results in semiconservative replication?the two resultng DNA molecules have one old parental strand and one new stand
The two resulting DNA strands from DNA replication areidentical DNA double helices, each with one old parental strand and one new strand
how does DNA encode genetic information?through the sequence of the DNA bases
how are DNA sequences read?in 3 letter "words" called "codons" (i.e. AGT)
mutationsinfrequent changes in the sequence of bases in DNA result in mutations

Section 8

Question Answer
true/ false: during replication, DNA polymerase mismatches nucleotides once every 1,000 to 10,000 base pairstrue
why is mutations in completed DNA strands so rare when DNA polymerase makes mistakes so frequently?there are proofreading enzymes that fix DNA polymerases's mistakes
what can cause DNA mutations?mistakes made in normal DNA replication, some chemicals cause them (i.e. cigarette smoke), and ultraviolet radiation or X rays can cause mutations
point mutations(nucleotide substitutions) involve changes to individual nucleotides in the DNA sequence
insertion mutationsoccur when one or more new nucleotide pairs are inserted into the DNA double helix
deletion mutationsoccur when one or more nucleotide pairs are removed from the double helix
inversion mutationoccurs when a piece of DNA is cut out of a chromosome, turned around, and re-inserted into the gap
translocation mutationwhen a chunk of DNA is removed from one chromosome and attachted to another

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