Basics of Chromosomes and Cell Cycle Introduction + Parts (Interphase focus) and Checkpoints Flashcards
DNA is in the
nucleus
what is the DNA before its a chromosome
Chromatin fibers are coiled and condensed it unorganized
when DNA is organized and copied its called
chromosome
centromere
is the dip in a chromosomes its a protein that joins the chromatids
how many chromosomes are in the body and how many pairs are there
23 pairs and 46 in the body
chromosome arm
Each chromosome is divided into two sections by the centromere and each section is the arm
chromosome duplication also includes
DNA synthesis
sister chromatids
one of the two identical halves of a chromosome that has been replicated in preparation for cell division. The two “sister” chromatids are joined at a constricted region of the chromosome called the centromere.
2 sister chromatids make up a
chromosomes
why do cells divide
1.reproduction for asexual organisms
2.growth and development
3.tissue renewal
one type of reproduction for asexual organisms
binary fission
how does cell division affect the growth of an organism
organism grow by adding cells
tissue renewal ex
repair damaged tissues and replacing layers of skin cells
the cell cycle is regulated
by cell communication
interphase is
between division
how long does interphase take
90% of the cells time
G1 (gap)
growth
-cytoplasm grows
-more organelles are added
S is
DNA synthesis this is where DNA is copied and is when 1 chromosome is duplicated by 2
G2
is more growth and its preparing the cell for mitosis
the m phase has what 2 steps overlapping eachother
cytokinesis and mitosis
why does the mitotic phase overlap
because when mitosis is ending cytokinesis starts
how long is the m phase
10% of the cells time
if the cells did not check of everything what happens
apoptosis (programmed cell death)
checkpoints in the cell cycle is when
checks of if the last phase did everything at the right time
