Chapter 4 Flashcards
Growth and Division of a Cell
this is the life cycle of individual cells
cell cycle
parent cells divide and produce what?
daughter cells
a process of producing new cells from the pre-existing cells
cell division
as parts of a plant reach their final form, most cells stop dividing, a process called?
cell cycle arrest
the cell cycle can be divided into two phases, namely:
growth phase and division phase
the part of the cycle without division is called?
interphase
in general, this phase is the longest part of the cell cycle
G1 (Gap 1)
during this phase, nucleotides are synthesized to be used for DNA replication
G1
during this phase, the cell is recovering from division; conducts most of its normal metabolism
G1
this phase is where the genes in the nucleus are replicated
S (Synthesis phase)
during this phase, thousands of genes are attached in a linear sequence forming a chromosome
S
this complexes with DNA and give it both protection and structure
histones
a chromosome has a centromere and is capped by what on each end?
telomere
some enter synthesis phase and replicate one or more times before differentiating, which is called?
endoreduplication
a process where only some genes are replicated, usually those needed for the specialized metabolism of the cell
gene amplification
during this phase, cells prepare for division
G2
during this phase, the alpha and beta tubulins necessary for spindle microtubules are synthesized
G2
during this phase, the cell produces proteins for processing
chromosomes and breaking down the nuclear envelope
G2
G1, S, and G2 constitues?
interphase
a term to describe the process of nuclear division
karyokinesis
what are the two types of cell division
mitosis and meiosis
meiosis: duplication division
mitosis: reduction division
a term to describe the process of cytoplasmic division
cytokinesis
under mitotic division, the number of phases sister chromatids are separated into daughter cells are? namely:
four phases; (PMAT) prophase, metaphase, anaphase, and telophase
during this division phase, the chromosome condense by coiling
prophase
during this division phase, the nucleolus becomes invisible, and the nuclear envelope breaks into vesicles
prophase
this is a protein layer on each chromatid
kinetochore
what pushes and pulls the chromosomes toward the cell center during metaphase?
microtubules
at the end of this phase in mitotic division, an enzyme breaks down the connection between sister chromatids
metaphase
when microtubules push and pull the chromosomes toward the cell center, what do they form?
metaphase plate
in this phase in mitotic division, spindle microtubules shorten and pull the twin chromatids toward opposite poles
of the cell
anaphase
this phase is mostly a reversal of prophase
telophase
as the chromatids reach each pole of the cell, complete nuclear envelopes form and surround each group of chromatids, what phase of mitotic division is this?
telophase
during this phase, chromosomes uncondense, new nuceloli appear, and spindle depolymerizes and disappears
telophase
no matter how the protoplast divides, each half typically contains what important cell membranes?
mitochondria, plastids, endoplasmic reticulum, and vacuoles
during this phase, the preprophase band forms just inside the plasma membrane
prophase
during this phase, the plane of division is identified, and the region where the new cell wall will attach to is marked
prophase
this is a set of short microtubules that forms in the center of the cell
phragmoplast
this traps dictyosome vesicles
phragmoplast
these are called the cell plate; grows outward until they fuse with those of a mother cell
phragmoplast, vesicle, and walls
this kind of division is accomplished with a phragmosome
vacuole division
vacuole division is accomplished with?
a phragmosome
this is a set of microtubules, actin filaments, and cytoplasm
phragmosome
this is referred to as reduction division
meiosis
this is referred to as duplication division
mitosis
what must be done to produce a diploid zygote?
haploid sex cells (gametes) must fuse together
this only occurs in the production of reproductive cells
meiosis
how many rounds of division is involved in meiosis?
two i.e. meiosis I and meiosis II
during meiosis, which phase does not occur after the first division?
S phase
prophase I is divided into five stages, namely:
(LZPDD) leptotene, zygotene, pachytene, diplotene, and diakinesis
during this phase in meiotic division, chromosomes begin to condense and become distinguishable but indistinct
prophase I
in meiotic division (prophase I), this stage is characterized by the synapsis of homologs
zygotene
this structure is present between the paired homologous chromosomes
synaptonemal complex
a synapsed pair of homologous chromosomes is called?
bivalent
during this stage in meiotic division (prophase I), chromosomes shorten and thicken
pachytene
during this stage in meiotic division (prophase I), the homologous chromosomes move away from each other but are held together by the centromeres
diplotene
this is the area of crossing over; a point where chromosomes are tangled together
chiasmata
during this stage in meiotic division (prophase I), the homologs continue to separate, and the chiasmata move toward ends until they untangle
diakinesis
this phase is wherehs the spindle microtubules move the homologs to the center of the cell, forming a metaphase plate
metaphase I
this phase involves the separation of homologs, moving to opposite ends of the spindle; two haploid nuclei have formed
anaphase I
this phase is where the chromosomes begin to uncoil, nuclear envelop forms and nucleoli appear
telophase I
if the cells progress to interphase, S phase does not occur, a process called?
interkinesis
in meiosis II, this phase prepares the nucleus for cell division (if telophase I has occured)
prophase II
which cell division do the centromeres divide at the end of metaphase II, separating the chromatids into two chromosomes?
meiosis II
in meiosis II, this phase pulls the separated chromosomes to each side of the cell
anaphase II
after meiosis II, each nucleus is?
a haploid
process of nuclear division where chromosomes is reduced in half
meiosis
process is identical to mitotic division, however results to four haploid daughter cells
meiosis II
multinucleate cells are also known as?
coenocytes
cell division may occur without nuclear division, which is commonly evident among?
algae, fungi, and the nutritive tissues of seeds
in many of these organisms, the nuclear envelope and nucleoli do not break down until mitosis
algae and fungi
the nuclei of this type of algae have no histones and chromosomes remain mostly condensed
dinoflagellates
in some green algae, cytokinesis occurs by use of a?
phycoplast
these are associated with divisions where the nuclear envelope does not break down
phycoplasts
in this type of algae, cell division occurs by a
phragmoplast , but the new wall grows inward
from the pre existing walls
red algae
cell division among prokaryotes are through?
binary fission
these type of organisms are where mitosis and meiosis do not occur
prokaryotes
this type of division process is where the circular DNA (plasmids) replicates, then are separated by membrane growth
(division by) binary fission
in binary fission, cytokinesis occurs by a process of?
infurrowing
which organelles involves their replication process appearing to be continuous throughout interphase
mitochondria and chloroplasts
the replication of organelles and their DNA is?
episodic
