Asexual Reproduction

Advantages No mate required Heredity is invariable ▫Offspring are genetic clones of the parent New individuals can be produced fairly quickly

Types Budding: a individual produces an outgrowth from which a new individual develops ▫Outgrowths detach and live freely ▫Example: strawberry plant and hydra Fragmentation: parts of the parent break off and grow independently ▫Example: fungi All types of asexual reproduction involve the same cellular process- mitosis

The Cell Cycle The sequence of events from one cell division to another; divided into phases The process of division is relatively short compared to the time it takes preparing to divide Interphase: between mitotic divisions; ▫cell grows and carries out normal function; genetic material is duplicated

Mitosis and Cytokinesis Mitosis: nuclear division when the genetic material in the nucleus divides equally into two identical nuclei This process has been divided into 4 phases: 1. Prophase4. Telophase 2. Metaphase 3. Anaphase Cytokinesis: division of the cytoplasm into two identical daughter cells

Prophase Chromosomes shorten and thicken becoming visible under a microscope Centrioles move to opposite poles of the cell Nuclear membrane and nucleolus begin to disintegrate

Metaphase The centrioles extend spindle fibres to the centromere of each chromosome (composed of sister chromatids) and pull them to the center of the cell Chromosomes align across the equator of the cell

Anaphase Centromeres divide and sister chromatids (now called chromosomes) move to opposite poles of the cell Same number and type of chromosome is found at each pole

Telophase Chromosomes reach the poles and unwind Spindle fibres dissolve Nuclear membrane forms around chromosomes = two daughter nuclei

Cytokinesis Immediately follows mitosis Cytoplasm and its contents divide into two daughter cells which are similar but may not be identical A furrow develops and the cell is pinched off into two parts

Videos 3D animation (1:22): uZYI&feature=watch_response Animation (1:30) Q&feature=relatedhttp:// Q&feature=related Cell Division (20s): ▫ ture=related

Homework Complete handout: Mitosis Read p.146 to 151 ▫Take point form notes ▫Define BOLD type terms Complete p.151 #1,2,4  9