Mitosis
Mitosis starts with 2n and ends with..
2n (diploid)
Meiosis starts with 4n and ends with..
n (haploid)
What happens in the S phase?
DNA is replicated and prepares to divide
What are somatic cells?
Every cell in the body except gametes
What info can you get from karyotypes?
Gender and if any disorders (monosomy or trisomy)
What are the haploid and diploid number of chromosomes in humans?
haploid- 23
diploid- 46
What is a nondisjunction?
Homologous chromosomes fail to separate properly (can happen in mitosis or meiosis)
What happens in meiosis 2?
Sister chromatids divide
What is fertilization?
Fusion of male and female gametes
What is a zygote?
When the sperm fertilizes the egg and it becomes diploid.
Role of spindle fibers
They split the centromeres of the sister chromatids. The sister chromatids separate, and they go to opposite poles.
What is a monosomy?
n-1, it has one less chromosome than normal
What is the result if cytokinesis doesn't happen?
The cell would have 2 nuclei and they would be attached
What are cyclins?
Group of proteins that regulate cells through cell cycle by activating cyclin dependant kinase
What are prokaryotic and eukaryotic chromosomes?
prokaryotic- circular, piece of DNA, doesn't have telomeres
eukaryotic- found in nucleus, DNA has a negative charge, more complex than prokaryotic
How many chromosomes in S Phase?
92
What is a trisomy?
n+1, it has one extra chromosome
When the cytoplasm of animal cells separate it is called..
Cleavage Furrow
What does anchorage dependent mean?
The cell needs to grow on a surface
What happens in metaphase of mitosis?
Spindle fibers split the sister chromatids
What happens during G1, G2 and G0
G1- cell grows and makes organelles
G2- cells makes more organelles so that it has them after division
G0- cells take a break, they don't prepare to divide
One major difference between meiosis and mitosis
Meiosis has genetic variability, so each haploid cell that it produces is different
How do plant cells separate during cell division if they have cell walls?
During Telophase, a cell plate forms across the cell in place of the metaphase plate. A new cell wall forms between the two membranes of the cell plate.
What is contact inhibition?
Once two cells touch each other, they stop growing (not cancer cells)
What is protein kinase?
Enzyme that modifies other molecules by adding phosphate group