The Cell Cycle And Mitosis Flashcards
During the cell cycle, what does a cell do?
A cell grows, prepares for division, and then divides to form two daughter cells, which then begin their own cell cycle.
What are the two main phases of the cell cycle?
Interphase and M
What are the three phases of Interphase?
G1, S, and G2
What are the two phases of M?
Mitosis and cytokinesis
What does G stand for in G1 and G2?
Growth, or gap.
What happens during G1?
Cell growth, organelles are copied
What happens during S?
The DNA is replicated in preparation for mitosis.
What happens during G2?
More cell growth, chromosomes checked for errors.
What are the four phases of mitosis?
Prophase, metaphase, anaphase, and telophase.
How long can the phases of mitosis last?
Anywhere from a few minutes to several days.
What is the cell cycle?
A series of events that cells go through during their lifetime.
What happens to the chromatin during prophase?
It condenses into chromosomes.
What happens to the centrioles during prophase?
They move to opposite sides and form fibers that will help pull apart the chromosomes.
Which is the longest phase of mitosis?
Prophase
In prophase, what are the fibers formed that have a specific job called?
Spindle fibers.
What happens to the nuclear membrane during prophase?
It breaks down.
What happens to the chromosomes during metaphase?
They line up across the equator of the cell.
What happens to the spindle fibers during metaphase?
They attach to the centromere of each chromosome.
What happens to the centromeres during anaphase?
The centromeres separate.
During anaphase, what does the separation of the centromeres cause?
The separation of the sister chromatids and making them become individual chromosomes.
What happens to individual chromosomes which are the product of anaphase?
They move to the opposite sides of the cell.
What happens to the chromosomes during telophase?
They become chromatid.
During telophase, what happens to the spindle fibers?
They break apart
What happens to the nuclear membrane during telophase?
It reforms round each cluster of chromosomes.
What happens to the chromatin during prophase?
It condenses into chromosomes.
What happens to the centrioles during prophase?
They move to the opposite sides of the cell and form fibers that will help pull apart the chromosomes.
What are the fibers formed during prophase called?
Spindle fibers
What happens to the nuclear membrane during prophase?
It breaks down
What happens to the chromosomes during metaphase?
They line up across the equator of the cell
What happens to the spindle fibers during metaphase?
They attach to the centromere of each chromosome
What happens to the centromeres during anaphase? What does this cause?
They separate, separating the sister chromatids into individual chromosomes
What happens to the chromosomes during anaphase?
They move to opposite sides of the cell
What happens to the spindle fibers during telophase?
They break apart
During telophase, are they chromosomes or chromatid?
They switch from chromosomes to chromatid
What happens during telophase to the clusters of chromosomes?
Nuclear membrane reforms around each one.
What is cytokinesis?
The division of a cell after mitosis or meiosis
Why do we need cytokinesis?
Because we now have one cell with two nuclei and the cytoplasm needs to split off to form two new cells
What happens to an animal cell during cytokinesis?
The cell membrane pinches in the middle
What happens to an plant cell during cytokinesis?
A cell plate forms between the two nuclei, eventually forming a cell membrane and cell wall
How do prokaryotic cells divide?
Binary fission.
What happens during binary fission?
DNA is copied, then cell membrane pushes inward between the two DNA copies and pinches off into two individual cells.
What is different about the DNA in Binary fission?
It’s circular.
How does a cell know when it’s time to divide?
The right presence of cyclins.
What are cyclins?
Special proteins that are present in different amounts throughout the cell cycle.
How do cyclins help the cell know when it’s time to divide?
Because of the amount of it present, it can help signal when the cell should proceed to the next stage.
What is cancer?
A disorder when the body’s own cells mutate and lose the ability to control growth.
What are tumors?
Masses of cells.
Why do cancer cells form tumors?
Because cancer cells don’t respond to signals that regulate the growth of most cells.
What can cause cancer?
Radiation, certain chemicals, or certain viruses, such as HPV.
Cell cycle
series of events cells go through during lifetime
