mitosis quiz Flashcards
what is the purpose of mitosis
cloning, copying, and division
mitosis
the process of cell division where a cell attempts to make an exact copy of itself -> reproduction and regeneration
A cell is always somewhere in the process of dividing. True or False?
False -> not constant, either doing their job or simply existing
In terms of DNA, what is the difference between G1 and G2?
G2 has twice as much DNA as G1
What happens to a cells chromosomes during prophase?
They condense
What happens to a cells centrosomes during prophase?
migrate to 2 poles
what happens during metaphase of mitosis?
they line up in a plane/single-file/role call for chromosomes
What do we call a place in the cell cycle where division pauses until certain criteria are met?
checkpoints
What criteria must be met before a cell can pass the G1 checkpoint?
Signal to divide, cell must be large enough, DNA must be undamaged, sufficient nutrition
What is the longest phase of mitosis? Why is this?
Metaphase, it includes a checkpoint within its process, must wait until everything is present and where it is supposed to be
What do cancer cells lack?
Social control, checkpoint control, apoptosis
What is the purpose of mitosis?
Cloning, Copying, and Division, Reproduction, Regeneration
Some cell cycle diagrams suggest that cells are always in the process of dividing. Are most cells that make up a mutli-cellular organism (like you and me) always dividing? why or why not?
No - ASK CAHOON SPECIFICS
What is a cell doing during G1 of interphase?
Existing, growing in size, preparing
What is chromatin?
The material which chromosomes are composed of, consists of protein, RNA, DNA
What is a centrosome?
A micro-tubular organizing centre.
Why would a cell move from G1 to S phase? What must have occured?
ASK CAHOON - Signaling?
What is happening during S phase of the cell cycle?
DNA replication/synthesis, centrosome synthesis
What is the chromosome # and DNA amount of our cell once it is in G2 of interphase? G1 had 10 chromo and 1x DNA amount
- ASK CAHOON, 20 chromo, 2x DNA amount
Sketch the appearance of chromosomes and centrosomes in prophase. What is the chromosome content and DNA amount in the cell?
SKETCH ON WHITEBOARD/IPAD - ASK CAHOON, 92?
Describe what is happening during prophase
Chromatin condenses to form x-shaped “metaphase” chromosomes, nuclear membrane dissolves, centrosomes migrate to 2 poles of the cell
Sketch the appearance of chromosomes and centrosome in metaphase. Include the three types of microtubules covered in class. What is the chromosome content and DNA amount in the cell?
SKETCH ON IPAD/WHITEBOARD/ Astral (membrane) , Polar (between the two) , and Kinetochore (chromosome)
Describe what is happening during metaphase.
largest phase of mitosis, centrosomes align all chromosomes along a central plane; role call for chromosomes, all must be present before mitosis can proced
Sketch the appearance of chromosomes and centrosomes in anaphase
SKETCH ON IPAD/WHITEBOARD
Describe what is happening in anaphase
The sister chromatids are separated when the kinetochore microtubules shorten and the polar microtubules lengthen; the sister chromatids (each is a full chromosome) are separate from one another; kinetochore microtubules shorten; polar -> push against one another & lengthen; astral -> shorten. Complete set of chromosomes are pulled to each pole.
Sketch the appearance of chromosomes and centrosomes in telophase
SKETCH ON WHITEBOARD/IPAD
Describe what is happening during telophase
Chromosomal migration is complete; The nuclear membranes from the chromosomes de-condense
Describe what is happening during cytokinesis
Microtubules form a ring around the plasma membrane and pinch apart into 2 separate cells
What is the chromosome content and DNA amount in each new cell? 2 new cells.
- ASK CAHOON, back to the start? 46? 1x?
Where are the cells chromosomes during interphase stage G1
- ASK CAHOON, nothing right?
What is the difference between a G1 and G2 interphase chromosome? Draw and describe each.
G1 is non replicated, G2 is replicated, 2 sister chromatids, doubled, G2 also has 2 centrosomes
What is the difference between a G2 interphase and metaphase chromosome? Draw and describe each.
- ASK CAHOON
Label each diagram below with the terms chromosome and chromatid, everywhere these terms are appropriate. - ASK CAHOON FOR CLARIFICATION.
- ASK CAHOON
What do we call a place in the cell cycle where division pauses until certain criteria are met?
Checkpoints
Where are the three cell cycle checkpoints we covered in this class?
G1/S, G2/Prophase, Metaphase
What criteria must be met for a cell to pass each checkpoint?
Signal to divide/permission, cell must be large enough/size, DNA must be undamaged, sufficient nutrition as well.
In terms of checkpoints, what do cancer cells lack?
social control, checkpoint control, apoptosis. they “bypass’ checkpoints in a sense.
What is apoptosis and how does it relate to cancer cells?
Apoptosis is the process by which cells “self-destruct”, or commit suicide for the betterment of the process. How this relates to cancer cells is that cancer cells do not undergo apoptosis, and will continue through mitosis regardless if they meet the criteria.
Describe the key structural differences between a G1 interphase chromosome, a G2 interphase chromosome, and a metaphase chromosome.
- ASK CAHOON; G1 single, G2 sister, metaphase - the same? ASK CAHOON.
Name the stage of interphase represented by each of the diagrams below. (refer to 2021 quiz)
left : G1, right : G2 (one with fully copied centrosomes
List the three cell checkpoints discussed in class and include at least two criteria for each one that must be met before the cell can continue to divide
Sufficient nutrition, the cell must be large enough and DNA undamaged
Which stage of the cell cycle would this event occur? Dyad chromosomes align along a single plane
Metaphase
Which stage of the cell cycle would this event occur? DNA is replicated
G2/Interphase
Which stage of the cell cycle would this event occur? Dyad chromosome condense
Prophase
Which stage of the cell cycle would this event occur? Chromosomes exist as fully replicated strands of uncondensed DNA. The replicated copies are held together by a centromere.
G2
Which stage of the cell cycle would this event occur? Dyads pull apart into individual chromosomes
Telophase/Cyto - ASK CAHOON
Which stage of the cell cycle would this event occur? Chromosomes exist as unreplicated strands of uncondensed DNA
Cyto/G1 - ASK CAHOON
Which stage of the cell cycle would this event occur? The cell is existing
G1
Which stage of the cell cycle would this event occur? Centrosomes are replicated
S/G2 - ASK CAHOON
Explain the difference between an interphase and metaphase chromosome.`
- ASK CAHOON, GET A GOOD ANSWER
List the three checkpoints covered in class and list two criteria that must be met for a dividing cell to pass that checkpoint
G1/S G2/Prophase Metaphase; Sufficient Nutrition, Large enough/size; Signaled to divide
If a cell cannot pass through a checkpoint, what are its options?
Apoptosis - ASK CAHOON - what does it do to try and complete DNA replication?
Name one stage of the cell cycle you would expect to find each of the following structures. An unreplicated chromosome
G1 - ASK CAHOON
Name one stage of the cell cycle you would expect to find each of the following structures. A fully replicated chromosome and uncondensed dyad chromosome
G2 - ASK CAHOON
Name one stage of the cell cycle you would expect to find each of the following structures. A fully replicated and condensed dyad chromosome
Prophase
Name one stage of the cell cycle you would expect to find each of the following structures. Chromatin
Prophase
Name one stage of the cell cycle you would expect to find each of the following structures. A chromosome undergoing the process of replication
S/G2 - ASK CAHOON
Name one stage of the cell cycle you would expect to find each of the following structures. Two chromosomes that used to be sister chromatids being pulled to opposite poles of the cell
Anaphase
Name one stage of the cell cycle you would expect to find each of the following structures. Homologous pairs of chromosomes
Telophase
What is the purpose of mitosis?
Growth, Replacement, Division, Copying, Cloning, Regeneration
What defines telophase of mitosis?
Chromosomal migration ends
What defines anaphase of mitosis?
Copied chromosomes separate from one another
What defines cytokinesis?
The cytoplasm is separated into two cells
What defines metaphase of mitosis?
Dyads align along a single plane
What defines prophase of mitosis?
Chromatin condenses into dyads
What is apoptosis?
programmed cell death
How many centrosomes are present in the S phase of the cell cycle?
It is difficult to say because the centrosomes are being replicated in S phase - ASK CAHOON ABOUT THIS, ISN’T IT 2?
Which is NOT a cell cycle checkpoint?
Telophase
What is a dyad in relation to a chromosome?
A dyad is also called a metaphase chromosome, which is two identical chromosomes held together at the centromere - ASK CAHOON, IS DYAD THE SAME AS DIPLOID?
Which is NOT a G1 checkpoint criteria that must be met before a cell will begin the process of dividing?
The cell’s centrosome must have been faithfully replicated - ASK CAHOON, HOW IS THE CELL ABLE TO CONTINUE IF THE CENTROSOMES ARENT ENTIRELY REPLICATED
In the cell cycle, what has doubled between the G1 and G2 phases of interphase?
DNA
What is a cell doing during G1 of interphase
Existing
What is a centromere?
The central part of a chromosome where the two chromatids are held to one another
What is a centrosome?
The microtuble organizing center
A chromatid is a chromosome connected to a copy of itself. True or false?
True
KAP
Microtubulus, Kinetochore, Astral, Polar
I PMAT C
Stages of Mitosis/Cell Cycle - Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
