LECTURE 16 Flashcards
Cytokinesis
The plotting of cytoplasm in a eukaryote
- begins in late anaphase and continues through telophase
What’s forms at the membrane during cytokinesis
An actin-based contractile ring
- myosin motors use ATP to pull on the actin filaments to separate the cytoplasm.
What is the position of the cleavage furrow determined by
Mitotic spindle
In plant cells, nuclei seperate in mitosis, and then a ________forms during cytokinesis
Cell plate
The cell plate develops into the
Cell wall that divides the two cells
Cell cycle control
Regulating cell division in eukaryotes
Which checkpoints in interphase are the most important
G1
What are the 3 major checkpoints in interphase
1) G1/S checkpoint
2) G2/M checkpoint
3) mitotic (spindle assembly) checkpoint
G1/S checkpoint
- is there a single to divide?
- checks for a growth factor and if there isn’t one it enters G0 phase
G0 phase
A non dividing phase
External singles
Signal to divide
Internal signals
Large enough or enough nutrients
G2/M checkpoint
- DNA replication complete?
- DNA free of errors?
Mitotic (spindle assembly) checkpoint
Are all kinetochore s connected to the ends of microtubules; problems may occur.
What type of problems may occur if kinetochores dont attach properly to microtubules
A) both kinetochore aren’t attached
B) one kinetochore isn’t attached
What do impoper conditions in kitechore attachment prevent?
They prevent entry to anaphase; the cell will keep trying to make proper connections until both are connected.
Specific proteins at the kinetochore sense if a microtubule is attached; if it is not, then a. Signal inactivated the
APC, this prevents destruction securin and prevents anaphase
Why do cell device in serum and not plasma ?
It wasn’t due to the nutrients in serum, but something that had to do with blood clotting processes.
Fibroblasts make
collagen and other ECM components like fibronectin. When a wound occurs, fibroblasts divide and secrete ECM components to the wound
What is the protein that promotes cell division called
Platelet-derived growth factor
blood clotting requires platelets
Mutations occur ________ at _____ rates
Spontaneously Slow
Was the transformation permanent and/or heritable in Griffiths experiment
YES
Transformation
Change in genotypes and phenotype due to assimilation of foreign DNA
Viruses that infect bacteria are called
Bacteriophages
Bacteriophages
- cannot replicate on their own
- can transform bacteria
- made of nuclei acid (DNA) and proteins.
What to use to track the movement of DNA and protien after the virus infects the bacteria ?
Radioactive isotope
Which isotope to use to trach movement of DNA and why?
Use P32 because its incorporated in DNA which is what is transferred