Mitosis Flashcards
What human cell may be haploid?
Ovum (the egg itself) not the ovary cell (that makes the egg)
How are prokaryotic chromosomes organised?
As a looped chromosome in the centre of the cell.
What is a eukaryote?
Any organism whose cells contain a nucleus and other organelles enclosed within membranes
How many chromotids are in each chromosome (metaphase)?
2
Why does cytokinesis differ in animal and plant cells?
Because animal cells do not have a cell wall
In which stage if the mitotic cell cycle does the synthesis of DNA take place?
S phase
The two major checkpoints in the mitotic cell cycle control entry into which two of its phases?
G2 and G1
Which of these organisms was NOT used in initial cell cycle genetic research?
1) Yeast
2) Fruit Flies
3) Sea Urchin
4) Clams
5) Frogs
2) Fruit Flies
What does a kinase enzyme do?
Adds phosphate groups to other proteins
What enzyme removes phosphate groups?
Phosphotase
What are the two compoenents of MPF (maturation-promoting factor)?
P34 Kinase and a Cyclin
What happens to cyclin D as it the cell cycle progresses into M Phase?
It is degraded
Phosphorylation of p34 (Cdk) can activate it or be inhibitory. Phosphorylation of which one of these residues activates it?
1) Threonine 161
2) Threonine 14
3) Tyrosine 15
1) Threonine 161
The others inhibit it
What is the phenotype of Wee 1 mutants in fission yeast Schizosaccharomyces pombe?
Small Cells
In the control of the yeast and animal mitotic cell cycle at G2/M, what is the name of the protein that removes the inhibitory phosphates on the cyclin B/P34 kinase complex (cyclin B/cdc2 kinase complex)?
Cdc 25 Phosphatase
