Cell Division Flashcards
Dense packaging of chromatin, existing during mitosis and meiosis
chromosome
The region where the two chromatids are held together
centromere
1 set of chromosomes
haploid
2 sets of chromosomes
diploid
___ chromosomes are found in diploid and represent chromosome pairs from each ____. They are similar in ___, __ __ and ___ ___. Humans have ___ homologous pairs. Homologous chromosomes do not necessarily have identical __ ___
homologous, parent, length, gene position, centromere position, 23, nucleotide sequences
where microtubules emerge from during cell division
microtubule organizing centers
In animal cells, the microtubule organizing centers are the ____, which are composed of two ___ ___ to each other. Plants also have MTOCs, but they are not ____
centrosomes, centrioles, perpendicular, centrosomes
The microtubules that emerge from the centrosome are called __ ___, and they allow for the chromosomes and chromatids to be __ during cell division. Drugs that disrupt __ __ will disrupt cell division
spindle fibers, separated, microtubule formation
During cell division, spindle fibers attach to proteins called ____, located on the ___ region of the chromosome. This serves as an __ point and allows the spindle fibers to change the ___ of the chromosome during cell division
kinetochores, centromere, anchor, position
during prophase, the chromatin condenses into ____. The ____ disappears, but the nuclear envelope is still ___. The __ __ begins to form and the ___ begin to move towards opposite ends of the cell
chromosomes, nucleolus, intact, mitotic spindle, centrosomes
During prometaphase, the nucleus ____, the chromosomes condense further, and each chromatid is attached to a ____. The __ __ further develops and the spindle fibers begin to attach to the ____ of chromosomes
dissembles, kinetochore, mitotic spindle, kinetochores
During metaphase, the chromosomes are lined up across the center of the cell on the _ ___. The ___ have reached the opposite ends of the cell and the _ ___ is fully developed. All the chromosomes are attached to _ ___ via kinetochores. ____ is performed during this stage
metaphase plate, centrosomes, mitotic spindle, spindle fibers, karyotyping
During anaphase, the microtubules ___ and the chromatids are pulled apart. Each sister chromatid is now considered to be an individual _____. These are pulled to ___ ends of the cell
shorten, chromosome, opposite
In telophase, the ___ reappear, two __ ___ develop, and the chromosomes decondense back into ____. The __ ___ disappear.
nucleoli, nuclear envelopes, chromatin, spindle fibers
Cytokinesis occurs at the end of ___, and is the physical division to form two cells. In animals, the ___ ___ acts as a contractile ring to separate the cells and is made by __ and ____. In plant cells, a __ ___ develops between the two nuclei and fuses with the __ ____ separating the cells
telophase, cleavage furrow, actin, myosin, cell plate, cell wall
At the end of mitosis, there are two daughter cells that are ___, and the ____ and amount of it is identical to the __ ___
2N, DNA, parent cell
The process of meiosis produces ___ ___ cells. In meiosis I, separation of the _ ___ and _ ___ occurs. In meiosis II, separation of the _ __ occurs
4, haploid, homologous chromosomes, genetic recombination, sister chromatids
In prophase I, the __ and ___ disappear, and chromatin condense into chromosomes. The ___ spindle begins to form and centrosomes begin to move towards opposite ends of the cell. The _ ___ also pair up into ____, and __ ___ occurs. The microtubules begins to attach to the ___ of the homologous chromosomes
nucleolus, nucleus, meiotic, homologous chromosomes, tetrads, crossing over, kinetochores
Crossing over is the process of __ __ producing chromosomes that are unique at the genetic level. ___ is the region where crossing over occurs, creating genetic ___ in offspring
genetic recombination, chiasmata, diversity
___ is when homologous chromosomes pair up into ___. These are two chromosomes sitting on ___ of each other. This process is necessary for __ __
synapsis, tetrads, top, crossing over
In metaphase i, the _ __ are lined up across the __ __ and ___ are attached to kinetochores
homologous pairs, metaphase plate, microtubules
In anaphase I, the meiotic spindle shortens and the homologous pairs ___ and are pulled to opposite poles in a process called ___
uncouple, disjunction
during telophase I the _ __ redevelops and the chromosomes begin to ____, Each new daughter cell has a new nucleus that has ___ the number of chromosomes, making it ___. The chromosomes are not _ ___ to the parent cells due to recombination. Then, ___ occurs
nuclear envelope, decondense, half, haploid, genetically identical, cytokinesis
Prophase II is the same as prophase I but not __ ___ occurs
crossing over
In metaphase II, there are ___ the number of chromosomes as there were in metaphase i, and the sister chromatids are no longer ___ due to crossing over during _ ___
half, identical prophase i
In anaphase II, the ___ are pulled apart
chromatids
Telophase II and cytokinesis is the same as ___
mitosis
Genetic variation occurs during three events: __ __, ___ __ and ___ __ of gametes
crossing over, independent assortment, random joining
The ____ phase is the physical separation of a cell into daughter cells and includes both mitosis and ___
mitotic, cytokinesis
Cells spend the majority of their time in ____.
interphase
During G1, the cell ___ and increases in ___. _ ___ begins in preparation for cell division
grows, size, protein synthesis
During S, or ___, the DNA is _____. This is where __ __ are formed and ____ are replicated
synthesis, replicated, sister chromatids, centrosomes
In G2, the ___ replicates, the cell continues to ___, and the cell ___ that everything is ready to proceed with mitosis
organelles, grow, checks
Cells like __ and ___ cells are permanently in the ___ phase, a state of a cell that is not actively dividing. Cells like ____ ____ are reversibly in the G0 stage and will re-enter the cell cycle based on different ___ ____
muscle, nerve, G0, T cells, environmental cues
Cells that are reversibly in G0
quiescent
A cell that is permanently in G0
Senescent
When a cell grows in size, the ____ grows more rapidly in comparison to the __ ___. This makes the cell less function because a small _____ value makes cellular exchange of __ and ___ harder
volume, surface area, S:V, nutrients, waste
An increase in cell volume also causes the ___ value to increase. When this happens, the cells exceeds the ability of its genome to produce enough amount of ___ for cellular activities.
G:V, regulation
Cells like __ ___ cells are not capable of dividing but are capable of growing larger through ____. They sustain this by having multiple ____ which overcomes the G;V limit. They are also ____ instead of spherical, improving the ____ limit
skeletal muscle, exercise, nuclei, long, S:V
The first checkpoint is at the end of ___ and is called the ___ point. Cell growth is assessed and favorable conditions like __ __, necessary __ __, adequate __ ___, and __ ___ are required to pass into S
G1, restriction, sufficient nutrients, cell products, cell size, healthy DNA
The next checkpoint is at the end of ____. The cell evaluates the __ and __ of DNA replication to proceed into the mitotic phase
G2, accuracy, completion
The final cell checkpoint is during _____ and is called the __ checkpoint. The cell evaluates if all the sister chromatids are attached to a __ ___. Mitosis stops if it is not
metaphase, spindle, spindle fiber
If the cells fails the checkpoints it may enter ___ permanently, or undergo ___
G0, apoptosis
When a cell stops dividing when the surrounding cell density reaches a maximum
density-dependent inhibition
__ ___ demonstrates that cells only divide when attached to an __ ___. This prevents cells from multiplying while ___ throughout the body
anchorage dependence, external surface, floating
In cancer, mutated cells __ __ and increase in number. This causes a mass called a ____. A tumor is considered ____ when its cells break loose and travel to other tissues and organs, a process called ____
divide uncontrollably, tumor, malignant, metastasis
The ___ gene actively suppresses tumors, and ____ of the gene cause the cell to uncontrollably divide, leading to ___ growth.
p53, mutation, tumor
Cancer drugs can inhibit _____ to stop uncontrolled growth, for example, by disrupting the ability of ___ to separate chromosomes during anaphase
mitosis, microtubules
cells that are continuously dividing (ex. skin cells)
labile cells
cells that do not usually divide, but can be stimulated to as needed (ex. liver cells)
quiescent (stable) cells
Cells that have little to no capacity for cell division (ex. cardiac muscle cells)
fixed (permanent) cells
The chromosome number only changes when _ __ separate, and thus does not occur in __ __
sister chromatids, meiosis I
