True or false: all cells make copies of themselves in a growing embryo
What types of cells are constanly regenerating through cell division?
Red and white blood cell
and intestinal lining
What cells cannot divide after birth ?
What are the steps of the Cell cycle?
Mitosis (actual, active cell division)
-G1 ("growth-1" or "gap-1")-
-S (replication of DNA)
-G2 ("growth-2" or "gap-2")
G1 phase (first growth phase)
After mitosis, a dividing cell enters this stage
G1 takes 8-10 hours to completeif the cell is activelyt dividing, it prepares for the next division
Cell duplicates organelles and cytoplasmic components
In order to enter S phase, cell in must pass a checkpiont
If a cell cannot pass the G1/S checkpoint, or if cell is quiescent (not actively dividing), cell remains in G0
For example brain cells (neurons) spend a lifetime in G0
Cells that take longe than the totalof 24 hours to pas through the cycle also wait in G0
A liver cell divides onces every seven years spending all that time in G0 before passing onto S phase.
S phase (synthesis)
DNA is replicated (copied)
All DNA must be duplicated in preparation for cell division
this proccess takes about 8 hours
The cell finalizes its preparations for mitosis
Cell now carries dougle the amount of normal DNA
-in G1 had 46 DNA molecules, now has 92
Duplication of centromeres
Second checkpoint (G2/M) must be crossed
-no normal cells are locked in G2
After 4-6 hours cell enter mitosis
What is Mitosis?
Mitosis is the actual active division of the cellInterphase is not a true phaseof mitosis, but all other parts of cell cycle
-G1, G0, S, G2 are interphase
mitosis has 4 stages
What is the difference between Mitosis and Cytokinesis?
Mitosis is the process of nuclear division
genetic material must be parcelled equally between cells
chromosomes form, get pulled apart, dissolve
Cytokinesis is the process of cell division
plasma membrane between cells tightens like a rubber band and pinches of two cells where there was one before
this separates the genetic material, cytoplasm and organelles into two equal daughter cells
a segment of DNA that codes for a protien
a region of DNA tha is made into protein
Messenger RNA (mRNA) carries the code for a primary sequence of amino acids in protein
Module 5 obj. 4
Graphic objective 6. Explain the process by which pre-mRNA is edited to a messenger RNA.p.241
Graphic objective 8. Explain how mRNA is translated into protein
Graphic Objective 10. Define: codon, anticodon. Summarize the steps in mRNA translation to form protein.
Graphic Objective 21. Define dominant and recessive genes. Explain sickle cell anemia and albinism in terms of Mendelian genetics. Construct and analyze Punnet squares for analysis of dominant and recessive gen inheritance.