ch 9 cellular reproduction

What is cell division?

reproduction at the cellular level

What is the purpose of cell reproduction?

• repair injured tissue,

• growth and development,

• renewal of tissues

• asexual reproduction

3 categories of cells

1. Stem cells

2. Cells that can divide

3. Permanently differentiated cells

What are stem cells?

Stem cell- cells that develop into many different types of cells

1. self-renewal- always capable of reproducing, serve as a repair system for the body

2. non-stem cells- differentiated cells with special functions that lack the ability to self-renew or form other cell types. Ex. Blood cells, muscles

prokaryotic cell cycle

Binary fusion:

• the chromosome is replicated first

• the plasma membrane grows and pinches inward and the cell splits into 2 genetically identical daughter cells– this is asexual reproduction:

  • one individual, cloning to create identical daughter cells

asexual reproduction

one individual, cloning to create identical daughter cells.

It is efficient and fast,

genetic diversities of a population is very low.

Eukaryotic cell division

nucleus and organelles and many chromosomes

Eukaryotic cell cycle

series of events one cell undergoes to "split" into 2 daughter cells.

Interphase:

• G1- growth and differentiation = organelles double,

• S- synthesis of DNA/ chromosomes are replicated/ duplicated

• G2- cell growth and preps the cells for division, proteins made,

Mitosis: division of the nucleus (chromosomes moving, (prophase, metaphase, anaphase, telophase)

Cytokinesis- split the cytoplasm

Stages of mitosis

Prophase- thick and condensed chromosomes; nucleus disappears, spindle fibers form,

Metaphase- chromosomes line up in the middle of the cell (equator),

Anaphase- sister chromatids separate and move to opposite poles of cells,

Telophase- nucleus reforms and cleavage furrow appears in animal cells,