Cell Division and Cell Cycle Flashcards
(36 cards)
Cell cycle
G1 (Gap 1) > S > G2 (Gap 2) > M
Interphase consists of
G1, S, and G2
Interphase makes up _____ percentage of the cell cycle
90%
The mitotic phase makes up ____ percent of the cell cycle
10%
What happens in the G1 phase?
- Cell grows
- organelles duplicate
What happens in the S phase?
DNA synthesis/ DNA replication
What happens in the G2 phase?
Cell performs check
Some cells don’t undergo mitosis and thus they are stuck in the ____ phase
G0 (G-zero)
Phases of mitosis
Prophase
Metaphase
Anaphase
Telophase
What happens in prophase?
-Nuclear membrane breaks down
-Nucleolus breaks down
-Chromatin start to condense into chromosomes
-Centrosomes start to move
-Mitotic spindles start to form
-Cytoskeleton disassembles
What happens in metaphase?
-Chromosomes line up in the metaphase plate
-Centrosomes are at opposite poles
-Mitotic spindle fibers attach to centromeres (kinetochores)
What happens in anaphase?
-Spindle fibers shorten and pull the chromatids away to the poles
-Centromeres split to two
-Spindle fibers elongate the cell
What happens in the telophase?
-Seperate nuclei start to form
-Nuclear envelope reforms
-Chromosome starts to decondense into chromatin
-Mitotic spindle breaks down
-Cleavage furrow forms, and two cells pinch off
The division of the nucleus into two daughter nuclei
Karyokinesis
Karyokinesis
The division of the nucleus into two daughter nuclei
Cytokinesis
Cytoplasm duplicates into two
Cytoplasm duplicates into two
Cytokinesis
Chromosomes and chromatids count during the Mitotic cell cycle
Cells that are in the G-0 phase
- Cardiomyocytes
- Skeletal muscle cells
- Hepatocytes
- Neurons
- Erythrocytes
Cell types due to the frequency of division
- Labile cells (under constant division)
- skin cells
- hematopoietic stem cells
- mucosal cells - Stable (Quiescent cells) normally in G0 phase but can proliferate when stimulated
- hepatocytes
- renal tubular cells
- fibroblasts
- smooth muscle cells - Permanent cells (Do not and cannot divide, stuck in the G0 phase)
- neurons
- cardiac muscle cells
- skeletal muscle cells
- erythrocytes
Chiasmata
The place where crossing over occurs
The place where crossing over occurs
Chiasmata
What is synapsis
Synapsis is the crossing over of homologous pairs of chromosomes during meiosis, creating recombinant chromosomes.
the crossing over of homologous pairs of chromosomes during meiosis, creating recombinant chromosomes
synapsis
