Mitosis and Asexual Mitosis and Asexual ReproductionReproduction

Life Cycle of a CellLife Cycle of a Cell

Mitosis StageMitosis Stage: this is the stage in : this is the stage in which the cell’s nucleus duplicates which the cell’s nucleus duplicates and divides to form two new nuclei. It and divides to form two new nuclei. It has four (4) stages or has four (4) stages or Phases. Phases. These are Prophase, Metaphase, These are Prophase, Metaphase, Anaphase, and Telophase.Anaphase, and Telophase.

Formation of Body CellsFormation of Body CellsMITOSISMITOSIS

How do Cells reproduce?How do Cells reproduce?

  Cells reproduce through a process Cells reproduce through a process

called Mitosis.called Mitosis.

Mitosis – Cell DivisionMitosis – Cell Division

MitosisMitosis is a kind of cell division that is a kind of cell division that produces produces body cellsbody cells. It started when you . It started when you were conceived and it still continues now!were conceived and it still continues now!

Each body cell divides to produce 2 new Each body cell divides to produce 2 new body cells with the body cells with the same number of same number of chromosomes chromosomes ((diploiddiploid).).

When a cell reproduces, one cell becomes When a cell reproduces, one cell becomes two two identicalidentical cells. cells.

Life Cycle of a CellLife Cycle of a Cell

InterphaseInterphase: the cell spends most of : the cell spends most of its time developing and maturing. It is its time developing and maturing. It is getting ready to reproduce. This is the getting ready to reproduce. This is the stage in which the chromatin in the stage in which the chromatin in the nucleus develops into chromosomes. As nucleus develops into chromosomes. As the chromosomes begin to appear, the the chromosomes begin to appear, the nuclear membrane disappears. Then nuclear membrane disappears. Then the Chromosomes duplicate the Chromosomes duplicate themselves!! This is called themselves!! This is called Replication.Replication.

Life Cycle of a Cell - Life Cycle of a Cell - InterphaseInterphase

Stages of MitosisStages of MitosisProphaseProphase: Chromosomes have : Chromosomes have

duplicated to form 2 strands or a pair duplicated to form 2 strands or a pair of chromatids (This is called of chromatids (This is called ReplicationReplication). These are called ). These are called homologous chromosomes. Spindle homologous chromosomes. Spindle fibers form and attach to the fibers form and attach to the chromosomes.chromosomes.

Prophase of MitosisProphase of Mitosis

Stages of MitosisStages of Mitosis

MetaphaseMetaphase: Chromosomes line up : Chromosomes line up at the center or middle of the cell. at the center or middle of the cell.

Stages of MitosisStages of Mitosis

AnaphaseAnaphase: Chromosomes begin to : Chromosomes begin to pull apart. Spindle fibers pull them to pull apart. Spindle fibers pull them to opposite ends of the cell.opposite ends of the cell.

Stages of MitosisStages of Mitosis

TelophaseTelophase: The cell divides : The cell divides in half. Two identical in half. Two identical daughter cells are formed, daughter cells are formed, each having the same each having the same number of chromosomes as number of chromosomes as the parent cell. The division the parent cell. The division into two new cells is called into two new cells is called CytokinesisCytokinesis..

Telophase of MitosisTelophase of Mitosis

Life Cycle of a CellLife Cycle of a Cell

CytokinesisCytokinesis: this is the final stage : this is the final stage of the cell’s life cycle in which the of the cell’s life cycle in which the cell’s cytoplasm is equally divided for cell’s cytoplasm is equally divided for each new nucleus and the cell each new nucleus and the cell divides to form two new, identical divides to form two new, identical cells.cells.

CytokinesisCytokinesis

Asexual ReproductionAsexual Reproduction

This is Reproduction with only This is Reproduction with only one parent.one parent.

Offspring (children) are Offspring (children) are identical to parent.identical to parent.

Asexual Reproduction occurs Asexual Reproduction occurs in single-cell organisms, in single-cell organisms, simple animals and plants.simple animals and plants.

Asexual ReproductionAsexual Reproduction

The formation of a new individual The formation of a new individual from one parent. from one parent.

Mini-me Mini-me

(clones)(clones)

Who Reproduces asexually?Who Reproduces asexually?

Unicellular organisms (Ex: bacteria)Unicellular organisms (Ex: bacteria)Many simple animals (Ex: hydra)Many simple animals (Ex: hydra)Many plantsMany plants

Asexual ReproductionAsexual Reproduction

It takes place by mitosis (new cells It takes place by mitosis (new cells are identical to parent – clones).are identical to parent – clones).

It occurs rapidly and often, resulting It occurs rapidly and often, resulting in large numbers of offspring.in large numbers of offspring.

Several methods include: Several methods include: Binary Binary FissionFission, , BuddingBudding, , Spore Spore FormationFormation, , RegenerationRegeneration, and , and Vegetative ReproductionVegetative Reproduction..

Asexual ReproductionAsexual Reproduction

Occurs by Occurs by MITOSISMITOSISSame hereditary materialSame hereditary material IdenticalIdenticalUsually occurs fastUsually occurs fastMany offspringMany offspringNo gametes involved (sex cells)No gametes involved (sex cells)

Methods of Asexual Methods of Asexual ReproductionReproduction

Vegetative ReproductionVegetative ReproductionBinary fissionBinary fissionBuddingBuddingSpore formationSpore formationRegenerationRegeneration

Methods of Asexual Methods of Asexual ReproductionReproduction

1) Binary Fission1) Binary Fission: this is the simplest : this is the simplest form. form.

One parent divides into two One parent divides into two equal equal parts. parts. Each daughter cell (new cells) becomes a Each daughter cell (new cells) becomes a separate individual and grows to normal separate individual and grows to normal size.size.

No parent No parent is left – it becomes two is left – it becomes two individuals.individuals.

Common in bacteria, protozoa, and algae.Common in bacteria, protozoa, and algae.

Example Binary FissionExample Binary Fission

Methods of Asexual Methods of Asexual ReproductionReproduction

2) Budding2) Budding::Parent divides into two Parent divides into two UnequalUnequal

parts.parts.New individuals develop from buds New individuals develop from buds

on the outer surface of the parent on the outer surface of the parent organism.organism.

Common in yeast, hydra, sponges.Common in yeast, hydra, sponges.

Example of Budding Yeast Example of Budding Yeast CellsCells

Budding HydraBudding Hydra

Methods of Asexual Methods of Asexual ReproductionReproduction

3) Spores3) Spores: these are special cells that : these are special cells that are produced by special organisms.are produced by special organisms.

They are released by the parent, They are released by the parent, germinate.germinate.

Spores are produced by fungi, algae, Spores are produced by fungi, algae, and protozoa.and protozoa.

They are products of mitosis.They are products of mitosis.Common forms are bread mold and Common forms are bread mold and

mushrooms.mushrooms.

Examples of SporesExamples of Spores

Methods of Asexual Methods of Asexual ReproductionReproduction

4) Regeneration4) Regeneration::The ability of an organism to re-grow The ability of an organism to re-grow

body parts.body parts.Examples are starfish, hydra, Examples are starfish, hydra,

planaria, earthworms.planaria, earthworms.

Example of RegenerationExample of Regeneration

Methods of Asexual Methods of Asexual ReproductionReproduction

5) Vegetative Reproduction: 5) Vegetative Reproduction: this is this is also known as Propagation.also known as Propagation.

It involves plants that reproduce It involves plants that reproduce asexually using vegetative parts asexually using vegetative parts (roots, stems, or leaves).(roots, stems, or leaves).

Vegetative parts give rise to new Vegetative parts give rise to new plants.plants.

This is a natural process that can also This is a natural process that can also be produced be produced Artificially!!!Artificially!!!

Natural Vegetative Natural Vegetative ReproductionReproduction

This type occurs in This type occurs in NatureNature!! Some !! Some plants reproduce by plants reproduce by Bulbs, Corms, Bulbs, Corms, Tubers, Runners or by RhizomesTubers, Runners or by Rhizomes..

   A) BulbsA) Bulbs: these are short : these are short underground stems surrounded by underground stems surrounded by thick leaves. Examples are onions, thick leaves. Examples are onions, garlic, tulips, and daffodils. (Corms garlic, tulips, and daffodils. (Corms do not have thick leaves.)do not have thick leaves.)

Example of BulbsExample of Bulbs

Example of CormsExample of Corms

Natural Vegetative Natural Vegetative ReproductionReproduction

B) TubersB) Tubers: these are enlarged parts : these are enlarged parts of underground stems that contain of underground stems that contain food. Contain “eyes”, which are tiny food. Contain “eyes”, which are tiny buds. Examples are potatoes.buds. Examples are potatoes.

Example of TubersExample of Tubers

Natural Vegetative Natural Vegetative ReproductionReproduction

C) RunnersC) Runners: stems that grow : stems that grow sideways along the ground. Buds sideways along the ground. Buds root and produce new plants. root and produce new plants. Example is strawberries.Example is strawberries.

Examples of RunnersExamples of Runners

Natural Vegetative Natural Vegetative ReproductionReproduction

D) RhizomesD) Rhizomes: stems that grow : stems that grow sideways underground that contain sideways underground that contain nodes. Nodes give rise to new plants. nodes. Nodes give rise to new plants. Examples are ferns, irises, cattails, Examples are ferns, irises, cattails, waterlillies.waterlillies.

Example of Rhizomes: Example of Rhizomes: ginger plantginger plant

Vegetative Reproduction Vegetative Reproduction ReviewReview

BulbsBulbs: short, underground stems surrounded : short, underground stems surrounded by fleshy leaves (tulip)by fleshy leaves (tulip)

CormsCorms: same as a bulb without the fleshy : same as a bulb without the fleshy leaves (crocus)leaves (crocus)

TubersTubers: enlarged part of the underground : enlarged part of the underground stem which contain tiny buds called “eyes”stem which contain tiny buds called “eyes”

RunnerRunner: a stem that grows sideways and has : a stem that grows sideways and has buds (strawberry, many grasses)buds (strawberry, many grasses)

RhizomeRhizome: a thick, underground stem that : a thick, underground stem that grows sidewaysgrows sideways

Artificial Vegetative Artificial Vegetative ReproductionReproduction

This type was developed by farmers This type was developed by farmers and gardeners to grow plants with and gardeners to grow plants with desirable traits. Methods include; desirable traits. Methods include;

Cutting, Layering, and GraftingCutting, Layering, and Grafting..

Artificial PropagationArtificial Propagation

Cuttings (leaf, stem, root)Cuttings (leaf, stem, root)LayeringLayeringGraftingGrafting

Artificial Vegetative Artificial Vegetative ReproductionReproduction

A) CuttingA) Cutting: a stem, leaf, or root : a stem, leaf, or root used to produce a new plant. These used to produce a new plant. These parts are dipped in a hormone and parts are dipped in a hormone and placed in moist soil. Examples are placed in moist soil. Examples are grapevines, roses, African Violets.grapevines, roses, African Violets.

Example of a CuttingExample of a Cutting

Artificial Vegetative Artificial Vegetative ReproductionReproduction

B) LayeringB) Layering: a stem is bent over : a stem is bent over and covered with soil to produce and covered with soil to produce roots. Examples are raspberries, roots. Examples are raspberries, roses, honeysuckle.roses, honeysuckle.

Example of LayeringExample of Layering

Artificial Vegetative Artificial Vegetative ReproductionReproduction

C) GraftingC) Grafting: Stems or buds are : Stems or buds are taken from one plant and joined to taken from one plant and joined to another stem of a related plant. another stem of a related plant. Examples, Fruit trees.Examples, Fruit trees.

Example of GraftingExample of Grafting

Tree GraftingTree Grafting