cell division
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what has the ability to replicate and pass on genes?
living things only
asexual reproduction results in what?
an exact copy of the dna
prokaryotes with single cells repoduce using what? how long does this process take?
binary fission, 10-20 minutes
do eukaryotic cells reproduce asexually?
yes
name three reasons why cells divide?
• to make copies of cells for growth(mitosis) • to make copies of cells for repairs • to carry on the species
before what cell event does dna replication occur?
cell division
describe the first step of DNA replication?
the two parental DNA strands seperate splitting the paired nucleotides apart the seperation occurs at the seperation fork
what is the function of DNA polymerase in replication?
creates a new complementary strand for the parent strand of DNA
how does DNA polymerase accomplish its task?
by following the base pairing rules of nucleotides
what is the word used to describe the results of DNA polymerase activity? why?
semiconservative, because every strand of DNA is half old and half new
name the four enzymes that aid DNA polymerase in replication?
• helicase • primase • DNA polymerase 1 • DNA ligase
what does the helicase enzyme do?
seperates the original parental strands opening DNA
primase enzyme has what role in replication?
lays out short RNA pieces called primers, which are needed for DNA plymerase to start copying
DNA polymerase 1 is an enzyme with what function?
removing RNA primers replacing them with DNA
what does DNA ligase do?
forms covalent bonds sealing small breaks created by the starting and stopping of replication
what is unique about the chemistry of the double helix?
it is chemically opposite on each end of its polarity
the chemical polarity allows for what unique advantages?
• allows hydrogen bonds to connect to each chemical rung of DNA • each strand is antiparrallel
what problems are caused by the anti parrallel structure of DNA?
DNA polymerase can only make new strands by lining up nucleotides in one direction this causes 2 processes for replicating DNA
what is unique about the first process in which DNA polymerase replicates DNA?
• the strand in which the 3’ end of DNA points towards the seperation fork can be replicated continuosly • this strand is called the leading strand
how is the chemically opposite polarity of the double helix represented?
3’,5’
what is unique about the second process in which DNA polymerase replicates DNA?
• this strand is called the lagging end • the 3’ end points away from the separation fork • DNA polymerase on the lagging end must work away from the separation fork and then return to the separation fork • ligase is complete the process with covalent bonds
the segments created on the lagging end are called what?
okazaki fragments
cells are dividing or not dividing, what is the name of this cycle?
cell cycle
what phase is a non dividing cell considered to be in?
interphase