exam 1 bio 111
explain the steps of binary fission
-cell increases in size -circular bacterial chromosome is reduplicated -replication begins at the origin of reduplication + proceeds in both directions to the site of termination -new chromosomes separated and partitioned to opposite ends of the cell -septation -septum divides the cell completely into two new daughter cells
what is the first level of DNA compaction?
DNA is looped around SMC proteins to form loop domains
What phases make up interphase?
G1, S, G2
which phase of the cell cycle carries out metabolic activity before DNA replication
G1- this is also the first gap phase
what is the first checkpoint in the cell cycle checkpoints and what is it regulated by
G1/S transition (start or restriction checkpoint): the commitment to divide -regulated by cyclin/CDKs
what phase metabolizes and prepares for DNA segregation (post-DNA replication)
G2 - this is also the second gap phase
what is the 2nd checkpoint in the cell cycle checkpoints and what is it regulated by?
G2/M transition: commitment to proceed to mitosis DNA is completely replicated -regulated by cyclin/ CDKs
what three genes regulate production of the FtsZ protein
Kai A, B, C
What is the name of the group of proteins involved in the compaction and organization of bacterial DNA in the nucleoid?
Structural maintenance of chromosome (SMC) proteins
what happens when telomeres become too short?
The cell can no longer divide
What is septation?
a new membrane and cell wall material form and create a septum at the midpoint of the cell
Membrane-bound organelles are _ in prokaryotes
absent
getting phosphorylated can _ an enzyme
activate
what results from activated CDKs
activation of specific genes that are necessary to advance in the cell cycle
what does it mean to phosphorylate
add a phosphate group
when do most cells stop producing telomerase? why?
after embryonic development this protects against unregulated cell growth
what is APC and is it a cyclin/CDK complex?
anaphase promoting complex NO
binary fission is a form of _ reproduction
asexual
which kind of organisms are unicellular
bacteria
Bacteria divide by
binary fission
How do bacteria reproduce?
binary fission
what can happen if cells divide uncontrollably?
cancer
what happens if the cell does not pass one of the checkpoints
cell division is halted or cell death happens
_ _needs to be controlled and responsive to ____ conditions
cell division, environmental
what is the area of repetitive DNA sequence
centromere
what is chromatin
chromosomal DNA associated with proteins
During binary fission ___ are replicated and partitioned for cell division.
chromosomes
the DNA in prokaryotes is ___
circular
what is the inner part of the centromeres
cohesion proteins
What are chromosomes?
condensed molecules of DNA associated with proteins
what do cyclins regulate?
cyclin dependent kinases (CDKs)
this class of proteins controls the cell cycle in part
cyclins
When does the cytoplasm divide into 2 cells?
cytokinesis
individual chromosomes are distinguishable in ____
dividing cells
what does asexual reproduction require
duplication and segregation of genetic material -division of cytoplasm
Cells only divide
during the day
plants, animals, protists, fungi are
eukaryotes
T/F: nucleus is present in bacterial cells
false
a chromosome contains a particular set of
genes
Cell division in bacterial cells and eukaryotic cells involves the replication and segregation of ______ information and the division of contents within the cell.
genetic
what is found within the nucleoid
genetic material
What are cyclin-dependent kinases (Cdks)?
kinases that are inactive unless they're attached to a cyclin protein
what are the site of microtubules attachment during cell division
kinetichore proteins
what is the outer part of the centromeres
kinetichore proteins
what is the cell size of eukaryotes
large
DNA has what kind of charge?
negative
What is the G0 phase?
non dividing state
individual chromosomes are not distinguishable in ___
nondividing cells
The bacterial genome consist of a single loop of DNA located in which of the following regions of the cell?
nucleoid
The region in a bacterial cell where DNA is located is called the
nucleoid
the _ is a non-membrane bound region of compacted DNA (and proteins)
nucleoid
what is the basic unit of chromatin
nucleosomes
what is meant by asexual reproduction
one cell divides into two cells
In bacterial cells, the replication of DNA begins at a specific site called the ____ of replication, and proceeds in both directions around the circular DNA until a specific____ site is reached
origin, termination
During the segregation of the duplicated bacterial chromosome, which part of the chromosome moves towards opposite ends of the cell first?
origins of replication
these are enzymes that dephosphorylate other molecules
phosphatases
what kinds of organisms are multicellular
plants and animals
Histone proteins have what kind of charge
positive
membrane-bound organelles are _ in eukaryotes
present
What's apoptosis?
programmed cell death
bacteria are
prokaryotes
_ have less genetic material than _
prokaryotes, eukaryotes
telomeres are repetitive sequences of DNA that _ + _ the ends of _
protect, stabilize, chromosomes
during cell division, two types of _ attach to the centromere of each _ _.
proteins, sister chromatid
what kinds of organisms are multi and/or unicellular
protists, fungi, yeast
in 90% of human cancers, telomerase production has been _
reactivated
what are cyclins
regulatory proteins that accumulate and degrade in a cell-cycle specific fashion
what does it mean to be dephosphorylated
remove a phosphate group
Binary fission involves ___and partitioning of chromosomes for cell division.
replicating, copying, duplication, replicating, or duplicating
what is compacted further into supercoils
selenoids
what is the cell size of prokaryotes
small
what is the 3rd checkpoint in the cell cycle checkpoints and what is it regulated by?
spindle checkpoint: commitment to segregate the replicated DNA to opposite ends of the cell chromosomes are properly aligned -regulated by APC
what is initiation
starting of the process and bringing together all the necessary enzymes to replicate DNA
The group of proteins involved in the compaction and organization of bacterial DNA in the nucleoid is called____maintenance of ___proteins
structural, chromosomal
what does the S stand for in S phase and what happens?
synthesis; DNA replication
telomere length can be maintained by which enzyme?
telomerase
each time a cell divides, the _ become shorter
telomeres
what facilitates septation?
the FtsZ protein
cell division in Eukaryotes is under strict genetic control in a process called ___
the cell cycle
what happens when CDKs are activated by cyclin
they can phosphorylate and activate target proteins that are necessary to advance in the cell cycle
T/F: nucleus is present in plant cells
true
True or false: Bacterial cell division produces genetically identical daughter cells.
truuu
what is the length of an E.Coli cell
~2 um
this is a protein enzyme that phosphorylates other molecules
kinases
Bacterial cells divide to produce new cells for which of the following? 1.) population growth 2.) genetic diversity 3.) reproduction
1 and 3
The FtsZ protein is necessary for bacterial cells to perform which of the following activities? 1. septation 2. elongation 3. replication of DNA 4. cell division
1 and 4
what 3 things does cell division require?
1.) replication of genetic material 2.) accurate segregation of genetic material 3.) division of cytoplasm between 2 cells
cell division is a key element of life that is important for these 4 things:
1.) reproduction 2.) growth 3.) wound healing 4.) replacing cells that die or are lost
chromosomes must be compacted to take up at least ____X less space in the cell
1000
there is a _ level of DNA compaction in dividing cells
higher
what do cohesion proteins do after DNA replication?
hold sister chromatids together
Cell division in bacterial and eukaryotic cells produces genetically ____ cells
identical
what are the 3 phases of DNA replication
initiation, elongation, termination
the cell cycle is an oscillation between ___, ___ and ___
interphase, mitosis, cytokinesis
The level of DNA compaction changes because
it's dynamic
the DNA in eukaryotes is __
linear
non-dividing cells have a _ level of DNA compaction
lower
what happens during M phase
mitosis (or meosis); DNA is segregated
what are sometimes collectively called 'mitosis' but are definitely separate events
mitosis and cytokinesis
what do eukaryotes divide by?
mitosis/meiosis
