Midterm - The Cell Cycle, Mitosis and Meiosis Flashcards
No living organism can reproduce without?
CELL DIVISION
They divide in order to reproduce.
UNICELLULAR ORGANISMS
This produces a continuous supply of REPLACEMENT cells in multicellular organisms.
CELL DIVISION
A cell cycle starts when __________, and ends when the cell ________.
NEW CELL FORMS; REPRODUCES
This is a series of events from the time a cell forms until its cytoplasm divides,
THE CELL CYCLE
What are the THREE (3) PHASES of THE CELL CYCLE?
1) INTERPHASE
2) MITOSIS
3) CYTOPLASMIC DIVISION
This is the interval between mitotic divisions when a cell grows, roughly doubles the number of its cytoplasmic components and replicates its DNA.
INTERPHASE
This is growth before DNA replication; the cell is metabolizing and growing in preparation for cell division!
G1 or 1st Interval (gap)
This is when DNA replication or when the DNA is being synthesized!
S or Interval of Synthesis
This is when the cell prepares to divide and produce a large amount of proteins need for division!
G2 or 2nd Interval (gap)
There are ______________ for the cell cycle in G1. If these are not removed, the division will not occur.
MOLECULAR BREAKS
Different types of cells proceed through the cell cycle at ___________ rates.
DIFFERENT
This regulate the cell cycle at different points!
GENE EXPRESSION CONTROLS
Loss of cell cycle controls result in ?
CANCER
The cell cycle has built-in __________ that allow problems to be corrected before the cycle advances.
CHECKPOINTS
These are gene expression controls that advance, delay, or block the cell cycle in response to internal and external conditions.
CHECKPOINT GENE PRODUCTS
In what CHEKPOINT is cell growth assessed at?
G1 CHECKPOINT
In what CHECKPOINT is DNA replication assessed at?
G2 CHECKPOINT
In what CHECKPOINT is mitosis assessed at?
M CHECKPOINT
Checkpoint genes whose products inhibit meiosis are called?
TUMOR SUPPRESSORS
Disruption of checkpoint gene products, such as by ________ or _______, causes _____ that may end up as ________.
MUTATIONS; VIRUSES; TUMORS; CANCER
Failure of cell cycle checkpoints results in the uncontrolled cell divisions that characterize ______.
CANCER
What gene plays a key role in the G1 checkpoint of cell division?
P53 GENE
This gene product, monitors the integrity of DNA.
P53 PROTEIN
If DNA is _______, the protein halts cell division and stimulates _______ ________.
DAMAGED; REPAIR; ENZYMES
If the P53 GENE is mutated, what happens?
- CANCEROUS CELLS REPEATEDLY DIVIDE
- NO STOPPING AT THE G1 CHECKPOINT
Normal or Abnormal P53?
Scenario:
Step 1: DNA Damage is caused by heat, radiation, or chemicals.
Step 2: Cell division stops, and p53 triggers enzymes to repair damaged region.
Step 3: p53 triggers the destruction of cells damaged beyond repair.
NORMAL p53
Normal or Abnormal P53?
Scenario:
Step 1: DNA Damage is caused by heat, radiation, or chemicals.
Step 2: The p53 protein fails to stop cell division and repair DNA. Cell divides without repair to damaged DNA.
Step 3: Damaged cells continue to divide. If other damage accumulates, the cell can turn cancerous.
ABNORMAL
Moles and other tumors are __________.
NEOPLASMS
This type of mole is noncancerous.
BENIGN NEOPLASM
This occurs when abnormally dividing cells disrupt body tissues, physically and metabolically,
MALIGNANT NEOPLASM (CANCER)
Malignant neoplasms can_____ ____ and _____ other tissues (________).
BREAK FREE; INVADE; METASTASIZE
A fertilized egg, zygote, divided by ?
MITOSIS