Cell Cycle Flashcards
MITOSIS
-is a process of cell division resulting in _ genetically (equivalent or not?) daughter cells.
2
Equivalent
All body cells divide by ____
mitosis
the germ cells divide by _____ to produce ____
meiosis
gametes.
The period between 2 cycles of mitosis is called the _____ which covers the __,___,and___phases of cell cycle
interphase
G1, S, & G2
-the cell spends most of its life in the ___ phase of the interphase to make ___and ____
G1
organelles and proteins
During the ___ phase,the ‘_____’ phase, DNA is replicated from ___pairs to ____ pairs
S
Synthesis
23
46
During the G2phase, DNA has been replicated and the chromosome number is _n from the S phase so it just prepares for mitosis and makes _____ and Shii
4
mictotubules
In the interphase, chromosomes are (visible or not visible?) by light microscopy because_______
Not visible
chromatin diffuses throughout the nucleus
Mitosis ends with 2 identical cells (2n)
T/F
T
Prophase of mitosis
- Each chromosome is made of two genetically identical ____, joined by a ____.
- During Dna replication , genetic material is (loosely or tightly?) packed as ____.
chromatids
centromere
Tightly
chromatin
However, during mitosisDNA needs to be more tightly packed to allow for easier separation in telophase.
T/F
F
Anaphase
At the start of prophase of mitosis, chromatin begins condensing into chromosomes.
T/F
T
At the prophase of mitosis,
mitotic spindles begin to form.
T/F
T
Mitotic spindles are structures made from _____ that aid in the organisation and arrangement of ______.
-The spindles attach to an organelle known as the _______.
microtubules
chromosomes
centrosome
Each cell in mitosis has one centrosome
T/F
F
2
during prophase of mitosis, the centrosomes begin to move in opposite directions.
T/F
T
Prometaphase of mitosis
-In this stage the chromosomes are still condensing into their compact state.
T/F
F
They’ve finished
In prometaphase of mitosis ,The nuclear envelope begins to breakdown, allowingspindle fibres to attach to the chromosomes at a site called the ______
-The sister chromatids are attached to ____ that originate from the opposite _____, linking the two together.
kinetochore
spindles
centrosome
kinetochore is an area of the_____ found on each sister chromatid
centromere
kinetochore microtubules invade_____ and attach to_____
-polar microtubules push against each other , moving ____ apart
nuclear space; kinetochores
centrosome
Metaphase of mitosis
-At this stage, the chromosomes align upon a theoretical line known as the ______.
metaphase plate
In Metaphase of mitosis , The centrosomes have finished moving and are located at opposite ends of the cell.
T/F
T
In metaphase of mitosis
At this stage, the cell will check that all the chromosomes are aligned along the metaphase plate, with their kinetochores correctly attached.
T/F
At this stage, the cell will check that all the chromosomes are aligned along the metaphase plate, with their kinetochores correctly attached.
- This helps to ensure sister chromatids are split evenly between the two daughter cells.
- An error in chromosomal alignment or spindle attachment will result in the cell halting further progress until the problem is fixed.
Anaphase
- During this stage, sister chromatids are pulled to opposite ends of the cell.
- The spindle fibres contract, breaking the chromatids at the centromere and moving them to opposite poles of the cell.
- Spindle fibres not attached to chromatids will elongate the cell to prepare it for division.
Telophase
- In this phase the cell has elongated and is nearly finished dividing.
- Cell-like features begin to reappear such as reformation of two nuclei (one for each cell).
- The chromosomes decondense and the mitotic spindles fibres are broken down
Cytokinesis
- is the division of the cytoplasm to form two new cells.
- This stage actually begins between anaphase and telophase, however doesn’t finish until after telophase.
- To separate the two cells, a ring of protein (actin ring) pinches the cytoplasm along a crease known as a cleavage furrow.
- This splits the cytoplasm equally between the two cells.