Chapter 5 Flashcards
Phases of Mitosis
Prophase Metaphase Anaphase Telephase Cytokinesis
Mitosis
The process in which the nucleus divides
Prophase
~ first and longest phase
~ chromatin condenses into chromosomes & the nuclear envelope breaks down.
~ Centrioles separate & move to opposite ends
~ spindle fibers start
Metaphase
~ spindle fibers attach to the centromere of each sister chromatid
Anaphase
~ sister chromatids separate & centromeres divide
~ sister chromatids are pulled apart by shortening spindle fibers
~ each pair of sister chromatids move to opposite ends of the pole
Telephase
~ chromosomes being to uncoil and form chromatin
~ spindle fibers break down and new nuclear envelope forms
Cytokinesis
~ final stage
~ cytoplasm splits into two
~ cell divides (two daughter cells form)
Interphase
Three groups :
G1
S
G2
G1
~ Cells grow rapidly
~ makes proteins for DNA replication
~ copies organelles
~ prepares for division
S
~ cells DNA copied
G2
~ cell makes final preparations to divide
Meiosis
Type of cell division where the number of chromosomes is reduced to half.
~ homologous chromosomes separate and haploid cells form.
Meiosis 1
Prophase: nuclear envelope breaks down; chromosomes condense
Metaphase: spindle fibers attach to paired homologous chromosomes
Anaphase: spindle fibers shorten & chromosomes from homologous pair separate to opposite ends of the poles.
Telophase/cytokinesis: spindle fibers break down and new envelope forms. Cytoplasm divides.
Meiosis II
Prophase II: nuclear envelope breaks down & spindle fibers begin to form; centriole separates
Metaphase II: spindle fibers line up the sister chromatids of each chromosome
Anaphase II: sister chromatid separate & move to opposite ends of the poles
Telophas/cytokinesis II: spindle fibers break down; new envelope forms; cytoplasm divides & 4 haploid cells result.
Haploid
Cells that contain half the number homologous chromosomes found in other cells of organisms
Diploid
Cells that have twice the number of chromosome as gamete (parent reproductive cells)
