16.2 Reproduction of Somatic Cells Flashcards
What are the 3 important functions of Mitosis and Cytokinesis?
Growth
Maintenance
Repair
Why is growth an important function?
They enable organisms to grow from a single-celled zygote into a mature organism that may contain hundreds of trillions of cells
Why is Maintenance an important function?
They produce new cells to replace worn out or dead cells
Why is Repair an important function?
They can regenerate damaged tissues
What must be done to ensure that the 3 important functions are able to take place?
The genetic material of the parent cell must be replicated
The replicated chromatin must be condensed and organized as chromosomes in the nucleus
One complete set of chromosomes must be divided into each of two new nuclei
The cell cytoplasm must divide to produce two complete and functional daughter cells
What Phase of the interphase does DNA replication take place?
During the S Phase
What does the cell do during the G2 phase of cell division?
The cell begins manufacturing or assembling other materials it will require for mitosis or cytokinesis
What happens at the end of the interphase?
The chromatin consists of two identical sets of DNA and the cell is ready to begin mitosis
What are the 4 Phases of Mitosis?
Prophase
Metaphase
Anaphase
Telophase
What is the Prophase?
The first of the 4 phases in Mitosis
What happens during the Prophase?
The chromatin condenses into tightly packed chromosomes and nuclear membrane breaks down releasing the chromosomes into the cytoplasm
What do the Centrioles do during the Prophase?
They move part to opposite sides of the cell
What happens as the centrioles move apart during the Prophase?
A network of fibers called the Spindle Apparatus forms between the centrioles
What is each Spindle Fiber made of?
Microtubules
What are microtubules?
Hollow tubes of protein that facilitate movement of chromosomes within the cell
What is the second phase of Mitosis?
The Metaphase
What happens during the Metaphase?
The Spindle Fibers guide the chromosomes to the centerline of the cells and have them facing opposite ways
What do the Spindle Fibers attach to?
The centromere of each chromosome
What is the third phase of Mitosis called?
The Anaphase
What happens during the Anaphase?
Each centromere splits apart and the sister chromatids separate from each other and the spindle fibers that link the centromeres to the pole shorten and pull the chromatids to opposite poles
What is the result at the end of the Anaphase?
One complete diploid set of chromosomes has been gathered at each pole of the elongated cell
What is the Fourth Phase of Mitosis?
The Telophase
What begins the Telophase?
The chromatids reaching the opposite polls of the cell
What happens during the telophase?
The Chromatids unwind into the longer less visible strands of chromatin and the spindle fibers breakdown. A nuclear membrane forms around each new set of chromosomes and a nucleolus forms within each new nucleus
What follows the process of Mitosis?
Cytokinesis
What is cytokinesis?
The division of the cytoplasm to complete the creation of two new daughter cells
What happens during Cytokinesis in Animal Cells?
An indentation forms in the cell membrane along the equator which depends until the cell is pinched in two. The cytoplasm and the organelles divide equally between two halves of the cell
What is different in Mitosis in Plant and Animal cells?
Plant cells do not have centrioles but form the spindle apparatus
Instead of cell wall pinching during cytokinesis a membrane called the cell plate forms between the two daughter nuclei
