BIO Mitosis Flashcards
What are some goals of mitosis
- produce genetically identical cells
- continuity of genetic information (no variation)
- Cells are identical and have complete genome
What is the general process of before mitosis and during and after?
In interphase, there is the G1, S phase, and G2. Here, the cell spends most of its time. DNA must replicate in the S phase so that there are two sets of the nuclear information to be then split so that each daughter cell has the complete genome.
What type of chromosomes does each daughter cell have?
diploid (2 pairs of chromosomes) 2n
What is nuclear division?
Mitosis; this is the process of splitting the information and substances of the nucleus so that the cell can replicate. This includes PMAT but not cytokinesis.
Why is it important for DNA replication to occur? What happens if they don’t?
This is to ensure that each daughter cell has genetic information. Otherwise, they would be anucleate cells so they can’t produce proteins and won’t live very long. For example, red blood cells.
Why do we need mitosis?
growth of multicellular organisms
heal
reproduction
what is the cell theory of mitosis?
all cells come from existing cells
Cytokinesis
this is when the parent cell literally splits into 2 daughter cells. The nucleaus nor nuclear information gets replicated, only the cytoplasm and its organelles get divided in cytokinesis.
How is cytokinesis different in animal and plant cells?
Animal cells: contractile ring forms in the middle of both daughter cells. This ring gets smaller and smaller and forms a cleavage furrow. Then, the cell will split into 2. The ring is made of proteins called actin and myosis.
Plant cells: vesicles form a cell membrane between the two daughter cells. Cell wall is made by microtubule scaffold. This process happens in telophase.
compare mitosis and meiosis
meiosis creates haploid gametes
meiosis creates genetically unique daughter cells
meiosis splits chromosomes from 46 to 23 for each gamete
Meiosis has random assortment of genes which is where the dna from the chromosomes are cut and swapped
all this creates genetic variatoin
What is the prerequisite for both mitosis and meiosis
Before DNA replication: the chromatin organizes into a chromatid. Chromatids have a centromere in the middle.
After DNA replication: a chromosome is formed which is the conjunto de los dos sister chromatids. Se juntan por los cohesin loops!
Later after anaphase: the cohesin loops must break so that the sister chromatids can separate to opposite sides of the cell
What is a sister chromatid
This is an exact replica of the chromatid.
What must happen before cell division?
DNA replication
What is the difference with equal and unequal cell division
equal cell division is when the daughter cells have the same amount of cytoplasm and organelles as each other
Unequal cell division is when one daughter cell has more cytoplasm and organelles than the other
What happens to the nucleus and mitochondria during cell division?
Each daughter cell must recieve the dna as well as a nucleus. Also, mitochondria replicates on its own as it has separate dna.
Each cell must have at least 1 mitochondria.
What are some examples of unequal cell division?
- budding yeast which reproduces asexually
-Oogenesis which is eff production during meiosis
If one daughter cell has less cytoplasm and less organelles, its daughter cells won’t be viable oocytes and can’t mature into viable oocytes
What happens if a cell doesn’t receive a nucleus?
They would be considered anucleate cells and thus can’t produce proteins since it doesn’t have dna to transcribe nor translate. Then, they will live for less time.
- red blood cells
Explain the cytoskeleton’s role in mitosis
in prophase, the cytoskeleton disassembles into the microtubules; microtubule spindle forms
Then metaphase, the spindles attatch to the kinetichore of the centrosome of the chromosomes and the chromosomes are pulled to the equilatoral plate?
The microtubule motor of the kinetochore removes microtubles so that the chromatids move towards opposite poles
What is the process of mitosis?
PMAT
What is the process of prophase? Draw and identify micrograph
After the DNA replicates, the DNA organizes into chromosomes and the microtubules start to form. The nucleus begins to disappear.
What is the process of metaphase. Draw and identify the micrograph
This is when the spindles attach to the kinetochore of the chromosomes and pulls them to the equator. The nucleus disappears
What is the process of anaphase? Draw and identify the micrograph
the microtubule motor of the kinetochore works and breaks microtubules so that the chromosomes break down to sister chromatids and each go towards the poles of the cel.
What is the process of telophase? Draw and identify the micrograph
Telophase when the chromosomes go to polar ends and then with cytokenisis, the proteins of the contractile ring form inbetween and the cleavage furrow is formed. This then splits the cell into daughter cells.
- two new nuclei
- chromosomes dissassemble sot chromatin
What is metastisis
Metastesis is the process by which cancer cells travel through the blood stream to different parts of the body
What are the checkpoints in the cell cycle
GI–> checks that the DNA is correct, that the cell has grown enough (cyclin E and D apparently)
After G2–> cyclin b, cdk complex 1 and makes sure that the dna replicated properly
M phase–> metaphase to anaphase and ensures that the spindles were correctly placed
What is mpf
this regulates the transition from GII to mitosis
