Lesson 1: Foundations to Set the Stage – ANSWER
Focusing on Cellular Structure and Function – ANSWER
The Normal Cell Cycle – ANSWER -The cell cycle refers to the ordered seres of processes of
DNA replication and mitosis, or cell division
-Cell nucleus regulates these processes by gathering and processing complexes molecular
information
Interphase and Mitotic Phase – ANSWER Cell division produces two identical cells through
these two major phases
During interphase: – ANSWER Cell grows and DNA is replicated through the following three
steps:
1: First growth phase (G1 or first gap)
2: Synthesis phase (S phase)
3:Mitotic Phse (M phase)
First Growth Phase (G1 or first gap) – ANSWER -cells increase in size
-reproduce RNA
-“quality assurance” test that the cell will be ready to synthesis DNA
-Length of time is variable, can be from hours to days
Synthesis Phase (S phase) – ANSWER -DNA replicates
-Results in the formation of identical pairs of DNA (chromatids)
-which are attached a t the centromere
-lasts 2-10 hours
Mitotic Phase (M phase) – ANSWER -Replicated chromosomes are aligned, separated, and
move into 2 new, identical daughter cells
-takes about 30-60 minutes
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Major points of cell regulation are entry and exit from – ANSWER -G1 checkpoint
-S Phase
-G2 checkpoint
-M phase
Restriction Point – ANSWER -The transition from the resting phase into an actively dividing
phase (G0-G1) is a point where cellular transformation can occur
-During this time, cells pass through a transition phase known as a restriction point
-Extracellular growth factors trigger reentry into G1, and GF are required to send the cells past
the restriction point, or the point of no return
G0 Phase (resting phase) – ANSWER -After mitosis, cells may enter back into the G1 phase or
go into a resting phase, known as G0
-Most cells in the human body reside in G0
-Exceptions to this are those that are (Resting in G0 phase) – ANSWER -Exceptions to this are
those that are metabollically active, such as
-granulocytes
-and the epithelium of the GI tract
Cell Cycling Time – ANSWER Amount of time from mitosis to mitosis
Cell cycle video and image – ANSWER
http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_th
e_cell_cycle_works.html
Check points in the Cell Cycle: Keeping it All Under Control – ANSWER -The cell cycle is
carefully controlled through a series of checkpoints
-Variation in duplication or distribution of chromosomes during cell division can alter the genetic
information passed on to daughter cells, leading to cellular dysfunction and disease, such as
cancer
-These checkpoints monitor for DNA integrity and control progression through mitosis