Final Study Guide Part III Flashcards
Stages of the cell cycle
G1, S, G2, Mitosis
G1
Growth phase
Protein synthesis
Synthesis (S phase)
DNA is replicated
G2
Additional growth and preparation for mitosis
Mitosis
Process of cell division
Steps of mitosis
Prophase Metaphase Anaphase Telophase Cytokinesis
Prophase
Nuclear envelope disappears, centrosomes migrate to opposite poles, spindle fibers form and attach To centromeres
Metaphase
Chromosomes line up along the equator
Anaphase
Centromeres of each chromosome divide in half, spindle fibers pull sister chromatids toward poles
Telophase
Spindle fibers disappear, nuclear envelope reforms, chromosomes decondense
Function of mitosis for an organism
Means of asexual reproduction
All growth takes place through mitosis
How many cells are at the start and end of mitosis
Start with one, finish with 2
Steps of meiosis
Same basic cell cycle but cell division is now meiosis I and II
Prophase I
Nuclear envelope disappears
Centromeres migrate
Spindle fibers appear and attach to centromeres
Synapsid occurs where chromosomes find their homologous pairs— crossing over occurs
Metaphase I
Homologous chromosomes line up on random sides
Independent assortment
Anaphase I
Homologous chromosomes separate and move to poles
Telophase I
Nuclear envelope reforms, centrosomes return, spindle fibers disappear
Cytokinesis
Cell cleaves into 2, non-identical haploid daughter cells
Interkinesis
Cells grow slightly but no replication of DNA
Meiosis II
Each cell divides again. Essentially same as meiosis I.
In anaphase II sister chromatids separate and move to poles. 4 non/identity haploid gametes are produced
Function of meiosis
Reproduction of sex cells (germ)
Starts with one diploid cell, finish with 4 non/identical haploid cells
