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?