Mitosis & Asexual Reproduction

Mitosis What is it? A process of cell division in body cells (somatic cells). Involves one replication and one division of genetic material (DNA) Results in 2 daughter cells that are identical to each other. They have the same number of chromosomes.

How is Mitosis Used? Mitosis is used for: Growth Replacements of cells Asexual reproduction (in some organisms)

What is Reproduction? There are two types: The production of offspring (new organisms) There are two types: Asexual Reproduction – 1 parent Offspring are genetically identical to the parent and to each other. - Sexual Reproduction – 2 parents Offspring are genetically different and have different characteristics from parents.

Asexual Reproduction Involves Mitosis – a process of cell division in body cells (somatic cells) Involves one replication and one division of genetic material (DNA) Results in two daughter cells that are identical to each other. They have the same number of chromosomes.

Mitosis Overview Telophase Interphase Prophase Anaphase Metaphase

The Phases of Mitosis Remember…IPMAT!! Interphase Prophase Metaphase Not a true phase of mitosis Prophase Metaphase Anaphase Telophase

The Phases of Mitosis - Interphase Interphase – the period between cell divisions Not a true phase of mitosis The cell grows and carries on normal metabolism Genetic material (DNA) exists as chromatin thin thread like coils of DNA. Chromosomes replicate before division

Double stranded chromosomes are held together at the centromere What is Replication? Each single stranded chromosome (chromatid) makes an exact copy of itself, resulting in a double stranded chromosome. This is important to make sure each cell created through mitosis has the same amount of DNA chromatid Double stranded chromosomes are held together at the centromere

The Phases of Mitosis - Prophase Chromosomes become visible. The nuclear membrane disappears. Spindle fibers form between centrioles (in animal cells only). Early Prophase Late Prophase

The Phases of Mitosis - Metaphase Double stranded chromosomes attach to spindle fibers at the centromere. Chromosomes line up on the equator of the cell.

The Phases of Mitosis - Anaphase spindle fibers shorten, pulling chromatids apart. cell membrane begins to pinch in (animal cells only). In plant cells a cell plate will form.

The Phases of Mitosis - Telophase Cell membrane begins to pinch in (animal cells only). In plant cells a cell plate will form. Cytokinesis occurs (division of cytoplasm) New nuclear membranes form Two new daughter cells are formed with identical nuclei. Cytokinesis Resulting Daughter Cells

Comparing Mitosis in Plant & Animal Cells Mitosis looks the same in plant and animal cells, except: Only animal cells have centrioles Animal cells pinch in In plants a cell plate is synthesized to divide cytoplasm.

Comparing Mitosis in Plant & Animal Cells Plant cells develop a cell plate during Telophase Animal cells have centrioles

Mitosis and Disease Cancer: A group of diseases characterized by an uncontrolled division (mitosis) of abnormal cells.

Asexual Reproduction Asexual Reproduction involves 1 parent and produces genetically identical offspring. Types: Binary Fission Budding Sporulation Regeneration Vegetative Propagation

Binary Fission Mitosis followed by equal cytoplasmic division. Ameba Paramecium

Budding Mitosis followed by unequal cytoplasmic division. Hydra Yeast Parent

Sporulation Special cells called spores are released from the parent and can develop into new individuals in a favorable environment. Bread Mold

Regeneration Planaria (worms) Sea Stars

Vegetative Propagation New plants develop from the roots, stems, or leaves of another plant. Occurs in some multicellular plants

Types of Vegetative Propagation Tubers (Potatoes) Cuttings Bulbs Runners

Vegetative Propagation Grafting – part of one plant (scion) is attached to another plant (stock). Stock Multi-grafted Citrus Tree Scion

PROPHASE PROPHASE INTERPHASE ANAPHASE PROPHASE METAPHASE INTERPHASE ANAPHASE TELOPHASE

Photos of 5 Stages