Mitosis: Division Is Also Multiplication Flashcards
Cell division starts with ______ which has 3 subphases
Interphase
3 subphases of interphase
G1
S
G2
Next 4 phases of cell division
Prophase
Metaphase
Anaphase
Telophase
______ are found in the different stages of cell division that monitor cell division, ensuring its smooth process
Checkpoints
G stands for
Gap
In ____, the cell synthesizes MRNA and proteins, which are needed for chromosome replication
G1
2 checkpoints in G1
G1 DNA damage checkpoint p53 proteins (TP53)
It evaluates the dna’s integrity
G1 DNA damage checkpoint
Damaged DNA results in the accumulation of p53 proteins that can trigger either _______ or _______
Cell cycle arrest or apoptosis
Are tumor-suppressing proteins that help in regulating the cell cycle
p53 proteins (TP53)
Refers to a process of programmed cell death
Apoptosis
It evaluates the cell’s capability to undergo cell division
Restriction checkpoint
If the cell is ready, it will proceed to S phase, if not, the cell goes to
G0
2 cells in G0
Quiescent (dormant)
Senescent (aging or deteriorating)
It may go back to cell division with proper stimulus
Quiescent cells
One reason cells become senescent is due to
damaged DNA
In this phase, chromosomes are replicated which means that there are twice the actual DNA now present in the cell
S (synthesis) phase
Each chromosome consists of two _____, which is one copy of a newly copied chromosome
Chromatids
It monitors the replication process during the S phase
S DNA damage checkpoint
At this point, the cell rapidly grows and protein synthesis continues
G2 Phase
It checks activities in G2 to ensure its proper flow
G2 DNA damage checkpoint
It ensures that DNA synthesis is complete before proceeding to mitosis
Unreplicated DNA checkpoint
The chromosomes condense and are now visible even with just using the ordinary light microscope
Prophase
A chromosome consists of two sister chromatids attached to the
Single centromere
In the late part of prophase, the ______ and the _______ disappear
Nuclear envelope and nucleolus
A special protein complex appears at the centromere at prophase. Its function is to link the spindle fibers to the centromere
Kinetochore
3 kinds of microtubles in the spindle fibers
Astral microtubules
Polar microtubules
Kinetochore microtubules
A kind of microtubules that grow only near the centrosome (the structure with the centrioles)
Astral microtubules
A kind of microtubules that grow away from the centrosome. These overlap ay the middle where the chromosomes are located, but they are still attached to the kinetochore
Polar microtubules
A kind of microtubules that are onlu ones attached to the kinetochore
Kinetochore microtubules
In metaphase, the kinetochore microtubule directs the chromosomes toward the center that is called
Metaphase plate or equatorial plate
It guarantees the proper alignment of the chromosomes at the metaphase plate and prevents untimely onset of the anaphase
Spindle assembly checkpoint
Twi substages in anaphase
Anaphase A
Anaphase B
In anaphase _, the kinetochore microtubules of the spindle fibers separate and move the sister chromatids toward opposite poles
A
In anaphase _, the polar microtubules begin to elongate, while astral microtubulea pull them on the other side.
B
Is the process of dividing the cytoplasm into half. It starts at anaphase and continues to the next phase
Cytokinesis
In _____, the chromosomes uncoil, and both the nucleolus and the nuclear envelope reappear
Telophase
Cytokinesis, in telophase, continues with the visible appearance of the _____, a groove on the cell membrane between the poles usually observed in animal cells
Cleavage furrow
In animal cells, the cleavage furrow is produced when the _______, which is made up of proteins, constricts the middle of the cell. This continues until the opposite surfaces of cell membrane are in contact and produces 2 daughter cells
Contractile ring
It prevents cytokinesis to start until all chromosomes are correctly separated.
Chromosome segregation checkpoint
The cell wall of plants is a strong substance thus a _________ forms which is involved in forming the cell wall of each daughter cell in plants
Cell plate
Mitosis ensures that the number of chromosomes of the parent cell is identical to
Its 2 daughter cells
46 chromosomes from parent cell
Two 46 chromosomes daughter cells
Purposes of mitosis
- ensures that the number of chromosomes of the parent cell is identical to its two daughter cells
- ensures the growth of the offspring
- replaces the damaged cells in the wounds
Is simply defined as cells that undergo continuous division without stopping
Cancer
