Asexual Reproduction and Mitosis SB2 e: Compare the advantages of sexual reproduction and asexual reproduction in different situations

Asexual Reproduction Occurs only through the process of mitosis Each offspring has the same genetic information Where can asexual reproduction be found? BACTERIA YEAST PLANTS

There are 5 different types of asexual reproduction. 1. Budding Parent divides unequally; new individuals develop from buds ex – yeast & hydra 2. Binary Fission Most simple form of asexual reproduction; Parent divides equally and results in two separate individuals Ex.-paramecium, bacteria 3. Spore Formation Single specialized cells that germinate when released from parent. Usually covered by a protective coating for preservation.

4. Regeneration/fragmentation Ability to regrow new body parts/ability to grow new Organism from parts. ex – hyrda, planaria, starfish, the bad guy from Terminator 2 5. Vegetative Reproduction/Propagation Refers to roots, stems, and leaves. Cells divide then differentiate to produce the same organism Ex.- strawberry plant, pick-a-back plant

Cell Cycle Mitosis Cytokinesis Period of time from one division to the next Unicellular division results in formation of new individuals of the species Cell Cycle Multicellular division results in replacement of old or damaged cells Process by which the nucleus divides while maintaining number of chromosomes Mitosis Cytokinesis Division of the cytoplasm Asexual Reproduction Reproduction that only involves one parent so therefore no special reproductive organs are needed

Interphase Prophase Metaphase Anaphase Telophase Cytokinesis Nuclear DNA wound around proteins known as histones Chromatin Condensed rolls of chromatin that are able to be seen during mitosis (rod-like structures) Chromosomes There are 5 phases in MITOSIS Interphase Prophase Metaphase Anaphase Telophase Cytokinesis

Interphase Interphase Known as “resting phase” Cells grow in size by producing more nucleic acids, proteins, and cellular organelles Chromosomes make copies of themselves, but they can’t be seen Nucleus of the cell is contained within the nuclear envelope Centrioles are present and duplicate themselves Interphase

Mitosis Begins Mitosis is the division of the nuclei Happens in somatic/ body cells

Draw a Chromosome One Double Chromosome Prophase Double chromosomes become visible - Chromatid Chromosomes are 2 sister chromatids connected by a centromere Draw a Chromosome Centromere Sister Chromatids One Double Chromosome

At the beginning, centrioles move to opposite poles Spindle fibers attach By the end, the nuclear envelope and nucleus have disappeared Prophase EARLY LATE DON’T DRAW

Metaphase= “Middle” Centromeres line up on the middle Metaphase

Anaphase Anaphase= “Away” Daughter chromosomes move to opposite sides of cell (poles) Anaphase

Telophase Telophase=“The End” Chromosomes uncoil and return to previous shape (threadlike) Nuclear membrane and nuclei reform Telophase NOTE: Cytokinesis begins during late anaphase and finishes during telophase

Cytokinesis Two identical daughter cells are formed. Each cell has the diploid (2n) number of chromosomes. In humans this is 46 chromosomes.

Mitosis in Plants Same as mitosis in animals except: Plants have no centrioles – spindle fibers take their place Asters do not form Cell wall does not pinch because it is too rigid Cell plate divides the cell into two