Baby Doe v. The Prenatal Clinic
Mitosis
Mitosis is a process of nuclear division in eukaryotic cells that occurs when a parent cell divides to produce two identical daughter cells. During cell division, mitosis refers specifically to the separation of the duplicated genetic material carried in the nucleus. Mitosis is conventionally divided into five stages known as prophase, prometaphase, metaphase, anaphase, and telophase. While mitosis is taking place, there is no cell growth and all of the cellular energy is focused on cell division.
Prophase - the first stage of mitosis.
-
The chromosomes condense and become visible
-
The centrioles form and move toward opposite ends of the cell ("the poles")
-
The nuclear membrane dissolves
-
The mitotic spindle forms (from the centrioles in animal cells)
-
Spindle fibers from each centriole attach to each sister chromatid at the kinetochore
Compare Prophase to the Prophase I and to the Prophase II stages of meiosis.
Metaphase
-
The Centrioles complete their migration to the poles
-
The chromosomes line up in the middle of the cell ("the equator")
Compare Metaphase to the Metaphase I and to the Metaphase II stages of meiosis.
Anaphase
-
Spindles attached to kinetochores begin to shorten.
-
This exerts a force on the sister chromatids that pulls them apart.
-
Spindle fibers continue to shorten, pulling chromatids to opposite poles.
-
This ensures that each daughter cell gets identical sets of chromosomes
Compare Anaphase to the Anaphase I and to the Anaphase II stages of meiosis.
Telophase
-
The chromosomes decondense
-
The nuclear envelope forms
-
Cytokinesis reaches completion, creating two daughter cells
Compare Telophase to the Telophase I and to the Telophase II stages of meiosis.
Interphase
-
is the "resting" or non-mitotic portion of the cell cycle.
-
It is comprised of G1, S, and G2 stages of the cell cycle.
-
DNA is replicated during the S phase of Interphase
