2C: Processes of cell division, differentiation and specialization Flashcards
Autosomal Cells
Diploid (2n) = 46
Haploid Cells
Haploid (n) = 23
Interphase
Consists of G1, S, G2; actively dividing cells spend most of their time in this phase
Interphase
Consists of G1, S, G2; actively dividing cells spend most of their time in this phase
G0
The cell is simply living and serving its function without any preparation for division
Interphase
Consists of G1, S, G2; actively dividing cells spend most of their time in this phase;
Chromosomes are in less condensed form known as chromatin (so that DNA is available for RNA Pol to transcribe)
G0
The cell is simply living and serving its function without any preparation for division
G1 Stage [Presynthetic Gap]
Cell creates organelles for energy and produces proteins while increases their size; contains a restriction point
G1 Stage [Presynthetic Gap]
Cell creates organelles for energy and produces proteins while increases their size; contains a restriction point
S Stage [Synthesis]
Genetic material is replicated so that each daughter cell will have an identical copy; each chromosome consists of two identical chromatids after replication
G2 Stage [Postsynthetic Gap]
Cell passes through another quality control checkpoint - makes sure that there are enough organelles and cytoplasm for both daughter cells
M Stage [Mitosis]
Consists of Prophase, Metaphase, Anaphase, Telophase and Cytokinesis
M Stage [Mitosis]
Consists of Prophase, Metaphase, Anaphase, Telophase and Cytokinesis
Prophase
Nucleus disappears, spindle forms, DNA condenses into chromosomes
Metaphase
Sister chromatids align along the equator of the cell by attaching their centromeres to the spindle fibers
Anaphase
Sister chromatids separate at the centromere and are pulled toward opposite poles of the cell by the mitotic spindle
Prophase
Chromosomes condense, nuclear membrane dissolves, nucleoli disappear, centrioles migrate and spindle apparatus forms
Metaphase
Chromosomes align along the equator of the cell by attaching their centromeres to the spindle fibers
Anaphase
Sister chromatids separate at the centromere and are pulled toward opposite poles of the cell by the mitotic spindle
Telophase
Nuclear membrane reforms and spindle apparatus disappears
Cyclins & Cyclin-Dependent Kinases
Rise and fall during the cell cycle controlling the activity of the cell cycle
Cancer
Occurs when cell cycle control becomes deranged, allowing damaged cells to undergo mitosis without regard for quality or quantity of the new cells produced
Metastasize
When cancerous cells produce factors that allow them to escape their site and invade elsewhere
Cyokinesis
Cytosol and organelles are split between the two daughter cells
Centriole Function
Organize the centrosome
Aster Function
Formed around each centrosome
Kinetochore
Protein structure on chromatids where spindle fibers attach during cell division
Kinetochore
Protein structure on chromatids where spindle fibers attach during cell division
Nuclear Membrane Breakdown
During Prophase and allows microtubules to attach at kinetochore
Nuclear Membrane Reorganization
During Telophase
How do chromosomes move?
By use of the spindle fibers during metaphase
Reasons for Growth Arrest
Genomic mutation/damage
Lack of nutrients
Contact Inhibition (once they get in contact with other cells they stop)
Reasons for Growth Arrest
Genomic mutation/damage
Lack of nutrients
Contact Inhibition (once they get in contact with other cells they stop)
Mechanisms that Control the Cell Cycle
Checkpoints within the cycle itself (G1 and G2), Spindle checkpoint; cyclins and CDK
Mechanisms that Control the Cell Cycle
Checkpoints within the cycle itself (G1 and G2), Spindle checkpoint; cyclins and CDK
Oncogenes
Genes that have the potential to cause cancer; can be due to mutations or excessive expression
Apoptosis
Programmed cell death; the cells contents are not released to the environment but rather digested intracellularly
Triggers of Apotosis
Cell Damage
Cell Mutations
Developmental Mechanisms
Immune Response
Prophase
Chromosomes condense, nuclear membrane dissolves, nucleoli disappear, centrioles migrate and spindle apparatus forms
Cytokinesis
Cytosol and organelles are split between the two daughter cells
Triggers of Apotosis
Cell Damage
Cell Mutations
Developmental Mechanisms
Immune Response
Meiosis
Produces four non-identical haploid sex cells (gametes)
Rounds of Meiotic Division
- Reductional
2. Equational
Meiosis I
Homologous pairs of chromosomes are separated from each other
Homologues
Chromosomes that are given the same number but are of opposite parental origin
Prophase I
Chromosomes condense, nuclear membrane dissolves, nucleoli disappear, centrioles migrate and spindle apparatus forms; additionally synapsis and crossing over occurs
Prophase I
Chromosomes condense, nuclear membrane dissolves, nucleoli disappear, centrioles migrate and spindle apparatus forms; additionally synapsis and crossing over occurs
Metaphase I
Homologues line up on opposite sides of the metaphase plate
Anaphase I
Homologues segregate to opposite poles of the cell
-Accounts for segregation and independent assortment
Anaphase I
Homologues segregate to opposite poles of the cell
-Accounts for segregation and independent assortment
Telophase I
Chromosomes decondense and the cell may enter interkinesis
Telophase I
Chromosomes decondense and the cell may enter interkinesis
Meiosis II
Same process as Mitosis
Spermatogenesis Outline
Spermatogonium -> Primary Spermatocyte -> Secondary Spermatocyte -> Spermatid
Spermatogenesis Outline
Spermatogonium -> Primary Spermatocyte -> Secondary Spermatocyte -> Spermatid
Spermatogonium
[2n]
A diploid cell that undergoes mitosis and creates a primary spermatocyte
Primary Spermatocyte
[2n]
Undergoes Meiosis I and produces a secondary spermatocyte
Secondary Spermatocyte
[n]
Undergoes Meiosis II and produces a spermatid
Spermatid
[n]
Matures into sperm
Oogenesis Outline
Oogonium -> Primary Oocyte -> Secondary Oocyte -> Ovum
Oogonium
[2n]
A diploid cell that undergoes mitosis to produce a primary oocyte
Primary Oocyte
[2n]
A diploid cell that undergoes meiosis I to produce a secondary oocyte
Secondary Oocyte
[n]
A haploid cell that undergoes meiosis II to produce an ovum
Site of Sperm Development
Seminiferous Tubules of the Testes
Sertoli Cells
Nourish sperm
Interstitial Cells of Leydig
Secretes testosterone and other androgens
Scrotum
Site of the testes
Epididymis
Give sperm motility and store sperm until ejaculation
Epididymis
Give sperm motility and store sperm until ejaculation
Ejaculation Pathway
Vas Deferens -> Ejaculatory Duct -> Urethra -> Penis