Mitosis
List all of the steps of Mitosis in order.
PMAT: Prophase, Metaphase, Anaphase, Telophase
Which stage of the cell cycle is the longest?
Interphase
If a cell does not pass all of the requirements of a checkpoint, what happens?
The cell usually remains at the stage it is at, until it meets all of the requirements.
In Prophase of Mitosis,
how many sister chromatids are there in one condensed chromosome?
two sister chromatids are joined to form one condensed chromosome
2 part question:
- After DNA replication, how many chromosomes does a human cell have?
-After DNA replication, how many sister chromatids does a human cell have?
46 chromosomes
and
92 sister chromatids!
Mitosis creates two daughter cells that are ______________ identical.
genetically
When a cell is "inactive" and does not divide anymore, it is said to be in the ________ ___________.
resting phase, or G0 phase.
Which checkpoint(s) assess for the availability of resources?
The G1 and G2 checkpoints
A fruit fly cell has 8 chromosomes.
AFTER this cell goes through mitosis,
the resulting daughter cells will have how many chromosomes?
8. They are genetically identical.
True or false?
Growth and development is possible without cell division.
Neither true or false.
Growth and development is possible without cell division in unicellular organisms.
In multicellular organisms, cell division is NECESSARY for growth and development.
What organelle helps arrange the spindle fibres during Mitosis?
Centrioles
List the phases of the cell cycle from beginning to end
Interphase (G1, S, G2) then Mitosis then Cytokinesis
True or False?
Once a cell enters the resting phase, it can no longer
re-enter the cell cycle.
False. A cell can re-enter the cell cycle if signalled to divide.
How many chromosomes does a human cell normally have?
46 chromosomes (23 pairs of chromosomes!)
How many nuclei does the cell have during metaphase of Mitosis?
0. The nucleus would have dissolved by now (in Prophase).
Cell division is useful for living things because...
cell division is useful for the
repair OR maintenance OR growth of an organism!
True or False?
Every cell in our body are at some stage of the cell cycle.
False. Some cells exit the cell cycle, and are at the resting phase.
A patient has brain damage from an injury and has little to no chance of recovery. This is because the brain cells...........? (finish the sentence)
Are in the resting phase
OR
Do not divide (they are inactive).
What can happen if a spindle fibre does not attach to a chromosome properly?
1) The spindle checkpoint ensures that the cell does not continue with mitosis until the spindle fibres attach properly.
OR
2) The resulting daughter cells end up having one extra or one less chromosome.
How is cytokinesis different in animal and plant cells? Explain.
In animal cells, the cell pinches in half, creating two daughter cells.
In plant cells, the cell does NOT pinch in half. Instead, a cell plate grows in the middle of the cell. The cell plate is created by vesicles recruiting in the middle. These vesicles contain all of the necessary ingredients to make a cell wall and cell membrane. The vesicles eventually fuse and split the plant cell into two cells.
At which cell cycle checkpoint must cells "commit" to dividing?
The G1 checkpoint.