Cycle 3 (Workshop + Study Session) Flashcards
What does “n” identify?
Identifies how many nuclear chromosomes are unique
Coefficient of n identifies:
How many set of n there are
Total number of chromosomes = Number of ___________
Centromeres
True or False:
N changes during mitosis
False, N does NOT change during mitosis
What is the coefficient of n also known as?
PLOIDY
True or False:
n and C have no correlational relationship
True
What is the C-value Paradox?
The debate over how C-value of an organism tends to increase with its “complexity”
However, there is debate over what “complexity” means
DNA is made up of 4 ___________
Nucleotides
Name and group the nucleotides that DNA is made up of
Purines = Adenine (A) and Guanine (G)
Pyrimidines = Cytosine (C) and Thymine (T)
Which nucleotides pair?
A-T, 2 bonds
C-G, 3 bonds
______________ bonds link nucleotides together
Phosphodiester
True or False:
DNA runs antiparallel
True
What is on the 5’ end of DNA? How about the 3’ end of DNA?
5’ end = Phosphate
3’ end = OH group
_______ unwinds the double helix to separate the 2 parent strands
Helicase
Explain how DNA Polymerase III works
DNA Polymerase III extends primers by adding nucleotides to form new DNA complementary to template strand
Explain how DNA Polymerase I works
Polymerase I cleaves off RNA primer and replaces it with DNA nucleotides
True or False:
DNA Polymerase III synthesizes new strand 3’-5’
False, DNA Polymerase III synthesizes new strand 5’-3’, but reads template strand 3’-5’
Define:
Leading strand
Continuous replication towards the replication fork
Define:
Lagging strand
Discontinuous replication away from replication fork (Okazaki fragments)
True or False:
Both leading and lagging strands begin with an RNA primer
True
Why are there often multiple origins (bubbles) during replication?
Increases replication efficiency
Each replication origin has _ ___________ _____ travelling in _______ __________
2 replication forks
Opposite directions
Explain how DNA ligase works
DNA ligase fills in the nicks left after removal of the primers
What are telomeres? What is their purpose?
Repeating TTAGGG sequences at the ends of your chromosomes
Acts as buffer regions
Define:
Hayflick limit
The number of times somatic cell can divide before reaching the end of the TTAGGG region
Define:
Cell senescence
Irreversible cell cycle arrest
DNA replication leaves the _ end of newly-synthesized strands _______ than their complementary strand
5’
Shorter
True or False:
Telomerase restores the length of chromosomes
True, but does not prevent DNA shortening
Describe how telomerase works
Binds to the 3’ end of template strand
Extends the length of the template strand using a short RNA template built into the enzyme
DNA polymerase III extends the RNA primer synthesized on newly extended template strand using complementary base pairing
