The Cell Cycle Flashcards
(27 cards)
By what 2 processes do eukaryotic cells divide?
Mitosis or Meiosis.
By what process do prokaryotic cells replicate?
Binary Fission
Can viruses replicate alone? Why?
No because they are non-living.
How do viruses replicate?
Inside of the host cells they invade by injecting their nucleic acid into the cell to replicate the virus particle.
What are the 3 stages of the cell cycle?
Interphase
Mitosis
Cytokinesis
What 3 stages make up interphase?
G1 phase
S phase
G2 phase
How much of the cell cycle does interphase take up?
90%
What occurs during interphase?
Organelles double
DNA replicates
The cell grows
What does mitosis create?
Two identical diploid cells.
Why do cells undergo mitosis?
For growth and repair.
Why do cells undergo meiosis?
To create gametes.
What does meiosis create?
Four genetically different haploid cells.
What is cytokinesis?
When the cytoplasm divides to create two new cells.
What occurs in the G1 phase?
Organelles double and cell grows.
What occurs in the S phase?
DNA replication
What occurs in the G2 phase?
Some more growth but also checking for mutations. Mutated cells are destroyed in this phase.
What are the four key stages of mitosis?
Prophase
Metaphase
Anaphase
Telophase
How many divisions does mitosis have?
1
What occurs in prophase?
The chromosomes become more visible. The centrioles separate and move to opposite poles of the cell.
The nucleolus disappears.
What are the centrioles responsible for?
For creating spindle fibres which are released from both poles to create a spindle apparatus.
What do plant cells lack?
They have a spindle apparatus but not centrioles.
What occurs during metaphase?
The spindle fibres align the chromosomes along the equator of the cell.
The spindle fibres attach to the centromere and chromatid.
What occurs during anaphase?
The spindle fibres start to retract and pull the centromere and chromatids. They are pulled to opposite poles of the cell.
This causes the centromere to divide into 2 and the individual chromatids are pulled to each opposite pole.
During anaphase, what are the separated chromatids now known as?
Chromosomes.
