Cell cycle And Cell Division Flashcards
1
Q
Stages of cell cycle?
A
- Interphase
- Nuclear Division (mitosis or meiosis)
- Cytokinesis
2
Q
Cell Division in eukaryotes, prokaryotes and viruses?
A
- Euk Cells enter cell cycle and divide by mitosis or meiosis
- Pro Cells replicate by binary fission
- Viruses don’t divide - non-living
- Viruses replicate inside host cells - inject their nucleic acids into cell to replicate virus particles
3
Q
What is interphase?
A
- Longest stage
- Organelles double, cell grows and then DNA replicates
4
Q
Types of Nuclear Division?
A
- Mitosis - two identical diploid cells, for growth and repair
- Meiosis - four genetically different haploid cells, gametes
5
Q
Cytokinesis?
A
- Final Stage
- Division of cytoplasm to create new cells
6
Q
Stages of Mitosis?
A
- Prophase
- Metaphase
- Anaphase
- Telophase
7
Q
Mitosis Key points?
A
- One round of division
- Genetically identical cells made
- Diploid cells made
- Growth and repair
8
Q
Prophase?
A
- chromosomes condense and become visible
- centrioles create spindle fibres - released from both poles of cell to create spindle apparatus
- Nucleolus disappears
9
Q
Metaphase?
A
- chromosome align along equator of cell
- spindle fibres attach to centromere and chromatid
10
Q
Anaphase?
A
- spindle fibres retract and pull the centromere and chromatids to opposite poles
- centromere divided in two and individual chromatids pulled it to each opposite pole - separated chromatids now are chromosomes
- stage requires energy (ATP) provided by respiration in mitochondria
11
Q
Telophase and Cytokinesis?
A
Telophase:
- chromosomes now at each pole of cell and become longer and thinner again
- spindle fibres disintegrate and nucleus starts to reform
Cytokinesis:
- cytoplasm splits in two to create two new genetically identical cells
12
Q
Mitotic Index Equation?
A
Number of cells in mitosis/total number of cells x 100
13
Q
Binary Fission in Prokaryotic cells?
A
- Replication of circular DNA and of plasmids
- Division of cytoplasm to produce 2 daughter cells - have single copy of circular DNA and variable number of plasmids
