Reproduction Asexual Reproduction

New organisms develop from cells of the parent – identical to parent

Asexual Reproduction All cells arise from other cells by cell division

Mitosis The exact duplication of the complete set of chromosomes Separation of these chromosomes into two complete sets Chromosome – contains hereditary information of an organism

Chromatid – one strand of a double-stranded chromosome Centromere – structure which joins the two chromatids together Chromatids Centromere

Mitosis Cytoplasmic division results in formation of two daughter cells Each daughter cell contains exact number & type of chromosomes as parent cell

Mitosis – The Process 1) INTERPHASE Replication of each single-stranded chromosome during the non-dividing period Results in a double-stranded chromosome

Mitosis – The Process 2) PROPHASE Disintegration of the nuclear membrane Synthesis of a spindle apparatus to help the division

Mitosis – The Process 3) METAPHASE Attachment of double-stranded chromosomes to spindle apparatus at centromere

Mitosis – The Process 4) ANAPHASE Replication of each centromere Results in formation of two single- stranded chromosomes Chromosomes move along spindle apparatus to opposite ends of the cell

Mitosis – The Process 5) TELOPHASE Nuclear membrane forms around each set of chromosomes Cell pinches in

Plant Mitosis vs Animal Mitosis Similar process In animal cells: – Centrioles form the spindle apparatus – Cytoplasmic division is a “pinching in” of cell membrane In plant cell, a cell plate is synthesized

Cancer Group of diseases often characterized by uncontrolled cell division of certain abnormal cells

Asexual Reproduction 1) Binary fission Equal division of cell of an ameba, paramecium, bacterium Result: Two equally sized organisms

Asexual Reproduction 2) Budding Unicellular organisms (yeast) – similar to binary fission except cytoplasm division is unequal New cells stay together (colony) or may detach

Asexual Reproduction Multicellular organisms (hydra) – Production of multicellular outgrowth from parent Detach or form colony

Obelia colony

Asexual Reproduction 3) Sporulation Spores – single, specialized cells Survive very well – withstand tough conditions Released from parent & develop into new individuals Ex- bread mold

Asexual Reproduction 4) Regeneration Develop of entire new organisms from part of parent Ex – starfish – develop from single arm Also refers to replacement of lost structures Ex – lobster regenerates a lost claw

Asexual Reproduction Invertebrate animals possess more undifferentiated cells than vertebrates Means that invertebrates can regenerate easier than vertebrates

Asexual Reproduction 5) Vegetative propagation New plants develop from roots, stems, leaves of parent plant

Asexual Reproduction Cuttings – Geranium Bulbs – Onion Tubers – Potato Runners – Strawberries Grafting – Seedless Orange