T4M1 Flashcards
The ability for a pre-existing cell to give rise to
another cell is due
the regulated process of cell division
prokaryotic cells, cell division is also
reproduction since the division of one prokaryotic cell will give rise to a new organism
(made up of one cell)
Prokaryotic reproduction
All of the essential elements necessary to reproduce cells are found in the prokaryotic cell. These cells are capable of making exact copies of their genomes and then segregating one copy of each genome to each of two daughter cells
The process of cell division in prokaryotes requires that
identical genetic material is distributed amongst daughter cells
In prokaryotes, the process of cell division is a form of
asexual reproduction that is often referred to
as binary fission
The process of cell division in prokaryotes is initiated when
the DNA of the bacterial chromosome is attached by proteins to the inside of the plasma membrane
DNA replication can then begin along
an origin of replication region of the bacterial chromosome
As the chromosome continues to replicate, the
cell begins to
elongate, and the newly synthesized DNA is also anchored to the plasma membrane
As binary fission progresses, the cell continues to
elongate until the two DNA attachment sites are at opposite ends of the elongated cell
When DNA replication is complete and the bacterium is approximately double its original size, the bacterial cell begins to
constrict along the midpoint of the cell along with synthesis od a new cell membrane and wall
Cell division in eukaryotes
mitosis
In eukaryotic organisms, cell division allows for a
unicellular fertilized egg to develop into a
complex multicellular organism
Early embryos contain
stem cells
Stem cells
unspecialized cells that can both reproduce indefinitely and under appropriate conditions, are able to differentiate into specialized cells of one or more type
Activation of satellite stem cells leads to
proliferation, differentiation and fusion of muscle precursor cells: myoblasts
Distinctions between prokaryotic and eukaryotic cell divisions is largely due to
eukaryotic DNA is larger, is organized
into linear chromosomes and is highly condensed into the nucleus of the cell
The process of cell division in eukaryotes requires more
regulated control as part of a larger cell cycle
Standard eukaryotic cell cycle two stages
interphase, M phase
interphase includes
the S phase (where DNA synthesis
occurs), and 2 gap growth phases G1 and G2
M phase is where
mitosis and cytokinesis occurs
With each mitotic cell division, the linear
chromosomes of eukaryotes must be
replicated and then separated into daughter cells
What stage do cells make preparations for cell division which include the replication of DNA in the nucleus, and an overall increase in cell size
interphase
Replication of DNA will occur in what phase?
S (or synthesis) phase
What phases prepare the cell for DNA synthesis and mitosis?
G1 and G2 phases