Cell Division & Mitosis Flashcards
Two main reasons cells divide
1 - If a cell grows to large, it will have trouble moving enough nutrients and wastes across the cell membrane
2 - The larger a cell b ecomes, the more demands the cell places on its DNA
What is cell division?
the process by which cellular material is divided between two new daughter cells
___ mother cell = ___ daughter cells
1 mother cell = 2 daughter cells
The two daughter cells will be _________ to eachother and to the mother cell
The two daughter cells will be IDENTICAL to eachother and to the mother cell
Each daughter cell is ____ the size of the parent cell, but immediately begins growing.
Each daughter cell is HALF the size of the parent cell, but immediately begins growing.
How many meters of DNA does a typical human cell have?
2 meters
before a cell divides all the DNA must be..
COPIED, and then the two copies separated so that each daughter cell ends up with a COMPLETE SET OF DNA
True or false? Each species has a characteristic number of chromosomes in each cell nucleus
True
How many chromosomes does a human?
humans have 23 pairs or 46.
Each cell must first copy its ________
before cell division occurs. Each daughter cell gets a complete copy of that information.
chromosomes
What are the two main stages of cell division?
Mitosis
Cytokinesis
What is Mitosis?
The division of the nucleus
What is Cytokinesis
The division of the cytoplasm
The chromosomes are not visible expect during…
The chromosomes are not visible except during CELL DIVISION
At the beginning of cell division, the chromosomes ___________________________________
condense into compact, visible structures that are easily seen with a microscope
Well before cell division takes place, each chromosome is __________ and __________
replicated and copied
At the beginning of cell division, each chromosome consists of __________
two identical “sister chromatids”.
What is the area of where two identical “sister chromatids” are connected?
A centromere
Replicated chromosome consists..
of 2 sister chromatids.
What is a cell cycle?
The series of events that cells go through as they grow and divide.
The cell cycle is the life of the cell from the time it is first formed from a dividing parent cell until its own division into two cells.
What happenes during the cell cycle? (3 steps)
- The cell grows.
- The cell prepares for division.
- The cell divides to form two daughter cells.
What are the 5 major phases of cell cycle?
1.) G1 [ First gap ]
2.) S [ Synthesis ]
3.) G2 [ Second gap ]
4.) Mitosis
5.) Cytokinesis
TWO NEW CELLS ARE THEN PRODUCED
What is Mitosis?
Mitosis is the division of the nucleus.
What is Cytokinesis?
Cytokinesis is the division of the cytoplasm.
Before a Cell Can Begin Mitosis and Actually Divide, It Must:
- It must form duplicates of its chromosomes.
- It must produce a supply of organelles for the two daughter cells.
These preparations occur during the G1, S, and G2 phases of the cell cycle.
These three (G1, S, and G2) are collectively known as interphase.
What is interphase?
G1
S
G2
G1 Phase
a) The cell doubles in size.
b) The enzymes, cytoplasmic organelles and other molecules double in number.
S phase
Replication of DNA occurs.
G2 Phase
The cell assembles the special structures needed for cell division
When interphase (G1, S, G2) is complete…..
the cell is ready to begin the process of cell division.
What accounts for 90% of the cell cycle?
Interphase
Mitosis has ____ stages…
Mitosis has 4 stages:
Prophase
Metaphase
Anaphase
Telophase