BISC 101 LATEST; QUESTIONS WITH
COMPLETE SOLUTIONS.
Cells features
1) structure
2)Function
3) Can reproduce
4) Have a cell cycle
Facts about cells
- All living organisms are comprised of cells
- Humans have 100 trillion cells with 200 cell types at birth
Purpose of cell division
1. Growth and Development
2. Replacement of dead/damaged cells
3. Reproduction
Which cells undergo cell division
- Cells that divide daily are skin cells, cheek cells, intestinal cells
- Cells that divide once a year are liver cells
- Cells which do not divide are nerve cells
The cell cycle must be _________?
- Process must be carefully regulated
- Cells cannot divide without regulation or else can lead to cancer cells
,Components of the cell cycle
0) G0 = cell resting phase
1) G1 = first gap phase where cell growth occurs
2) S = where synthesis of DNA takes place
3) G2 = second gap phase where cell prepare for cell division
4) M-phase = mitosis (nucleus divides)
What is the interphase in the cell cycle?
G1 = Growth
S = Synthesis (replicate DNA)
G2 = Cells prepare for division
Cell cycling time
G1 = 7-9 hr
S = 6-8 hr
G2 = 4-5 hr
M = 2-3 hr long
one cycle around 24 hr
How is the cell cycle regulated?
- "Mitosis Promoting Factor" (MPF) levels are at maximum as the cell enters mitosis
- Cyclin levels max as well
Mitosis Promoting Factor
, - protein kinase that must combine with cyclin molecule
- cyclin activates the kinase by adding phosphorylating it
- MPF is a cyclin dependant kinase molecule
Checkpoints in cell cycle
1) G1 = most important, if cell does not pass they go back to G0
2) G2 = MPF complex interacts here
3) M-phases = stop the cells from dividing during mitosis
Platelet Derived Growth Factor
- When tissues in the body are damages, there is a need for repair
- Can stimulate cell division to result in production of connective tissue to repair
Mitosis
- Production of genetically identical daughter cells
- DNA in nucleus is replicated
- Forms chromosomes of 2 sister chromatids joined at the centromere
Stages of Mitosis (PPMAT)
1) prophase = chromosomes appear with sister chromatids, spindle apparatus forms
2) Pro-metaphase = nuclear envelope breaks down, microtubules attach to chromosomes at the
centromere
3) Metaphase = sister chromatids migrate to the middle of cell, spindle apparatus complete,
chromosomes line up
4) Anaphase = chromatids are pulled along by the kinetochore microtubules
COMPLETE SOLUTIONS.
Cells features
1) structure
2)Function
3) Can reproduce
4) Have a cell cycle
Facts about cells
- All living organisms are comprised of cells
- Humans have 100 trillion cells with 200 cell types at birth
Purpose of cell division
1. Growth and Development
2. Replacement of dead/damaged cells
3. Reproduction
Which cells undergo cell division
- Cells that divide daily are skin cells, cheek cells, intestinal cells
- Cells that divide once a year are liver cells
- Cells which do not divide are nerve cells
The cell cycle must be _________?
- Process must be carefully regulated
- Cells cannot divide without regulation or else can lead to cancer cells
,Components of the cell cycle
0) G0 = cell resting phase
1) G1 = first gap phase where cell growth occurs
2) S = where synthesis of DNA takes place
3) G2 = second gap phase where cell prepare for cell division
4) M-phase = mitosis (nucleus divides)
What is the interphase in the cell cycle?
G1 = Growth
S = Synthesis (replicate DNA)
G2 = Cells prepare for division
Cell cycling time
G1 = 7-9 hr
S = 6-8 hr
G2 = 4-5 hr
M = 2-3 hr long
one cycle around 24 hr
How is the cell cycle regulated?
- "Mitosis Promoting Factor" (MPF) levels are at maximum as the cell enters mitosis
- Cyclin levels max as well
Mitosis Promoting Factor
, - protein kinase that must combine with cyclin molecule
- cyclin activates the kinase by adding phosphorylating it
- MPF is a cyclin dependant kinase molecule
Checkpoints in cell cycle
1) G1 = most important, if cell does not pass they go back to G0
2) G2 = MPF complex interacts here
3) M-phases = stop the cells from dividing during mitosis
Platelet Derived Growth Factor
- When tissues in the body are damages, there is a need for repair
- Can stimulate cell division to result in production of connective tissue to repair
Mitosis
- Production of genetically identical daughter cells
- DNA in nucleus is replicated
- Forms chromosomes of 2 sister chromatids joined at the centromere
Stages of Mitosis (PPMAT)
1) prophase = chromosomes appear with sister chromatids, spindle apparatus forms
2) Pro-metaphase = nuclear envelope breaks down, microtubules attach to chromosomes at the
centromere
3) Metaphase = sister chromatids migrate to the middle of cell, spindle apparatus complete,
chromosomes line up
4) Anaphase = chromatids are pulled along by the kinetochore microtubules
