Objectives Name three parts of the cell cycle. Name four major parts of mitosis.
12
Objectives 1) Name three parts of the cell cycle. 2) Name four major parts of mitosis. 3) Identify important parts of a dividing cell. 4) Discuss important similarities and differences between mitosis and meiosis.
description
Objectives Name three parts of the cell cycle. Name four major parts of mitosis. Identify important parts of a dividing cell. Discuss important similarities and differences between mitosis and meiosis. The cell cycle has three major parts:. 1. Interphase. 2. Mitosis - PowerPoint PPT Presentation
Transcript of Objectives Name three parts of the cell cycle. Name four major parts of mitosis.
Objectives1) Name three parts of the cell cycle. 2) Name four major parts of mitosis.3) Identify important parts of a dividing cell.4) Discuss important similarities and
differences between mitosis and meiosis.
The cell cycle has three major parts:
1. Interphase
2. Mitosis (Karyokinesis)
(Mitosis has four major sub-parts)
1) Prophase
2) Metaphase
3) Anaphase
4) Telophase
3. Cytokinesis
InterphaseCharacterized by:1. Intact nuclear envelope2. Visible nucleolus3. Although you can’t tell it,
the cell’s DNA and other cell components are undergoing a process called replication (duplication process); chromosomes become double-stranded.
4. Three sub-phases: G1, S, and G2
Nuclear envelope
Nucleolus
ProphaseCharacterized by:1. Disappearing nuclear envelope
and nucleolus2. Chromosomes (46* in each
human cell) coil and condense
3. Spindle fibers (microtubules)form and chromosomes become attached by way of centromeres
4. Newly formed centrioles move to opposite ends of the cell
Condensed chromosomes(chromatin fibers)
*23 pairs of chromosomes
Mitosis = Karyokinesis
Metaphase Characterized by:
1. Chromosomes align across the “equator” or metaphase plate
2. Centrioles stop at oppositeends of the cell
3. Spindle apparatus is fully formed
Metaphase plateCentrioles
CentriolesSpindle
apparatus
Mitosis = Karyokinesis
AnaphaseCharacterized by:1. Spindle fibers (microtubules)
shorten and separate the chromosomes at the metaphase plate
2. In the human cell, 46 single-stranded chromosomes movein opposite directions toward each pole
Centrioles Centrioles
Shortening microtubules(spindle fibers)
Mitosis = Karyokinesis
Can you name structures in the dividing cell?
single-stranded chromosome centromere
centrioles
spindle fiber (microtubule)
TelophaseCharacterized by:1. Cleavage furrow forms2. Nuclear envelopes begin to
form around two daughter nuclei
3. Chromosomes decondense4. Spindle disappears
cleavage furrow
daughter nuclei
Mitosis = Karyokinesis
Cytokinesis (Division of cytoplasm and contents into two cells)
This figure represents an overview of the cell cycle.
This figure represents an overview of meiosis (human male)
This figure represents an overview of meiosis (human female)
MITOSIS MEIOSIS
All chromosomes align at metaphase plate
Homologous pairs of chromosomes align
One set of divisions:
P – M – A – T
Two sets of divisions:
PI - MI – AI – TI
PII – MII – AII – TII
2 daughter cells 4 daughter cells (male)
1 cell and polar bodies (female)
daughter cells diploid (2n; same as original cell)
daughter cells haploid (n; half chromosomes as original cell)
Growth and repair Formation of sex cells
Similarities and Differences
