Asexual ReproductionAsexual Reproduction

Living EnvironmentLiving Environment

• Mitosis animation:Mitosis animation:

• http://brodylab.eng.uci.edu/cgi-bin/jphttp://brodylab.eng.uci.edu/cgi-bin/jpbrody/animation/files/6-973887139.hbrody/animation/files/6-973887139.htmltml

Are you two twins?Are you two twins?• Asexual ReproductionAsexual Reproduction: :

– Used by many unicellular organisms, Used by many unicellular organisms, plants, and lower animals.plants, and lower animals.

– Involves only mitotic cell division = each Involves only mitotic cell division = each offspring has exactly the same heredity offspring has exactly the same heredity as its parent.as its parent.

– Usually rapid compared to sexual Usually rapid compared to sexual reproduction. Types of Asexual reproduction. Types of Asexual Reproduction Include:Reproduction Include:

Cut it halfCut it half• Binary Fission Binary Fission = =

simplest form of simplest form of asexual asexual reproduction. reproduction. Parent organism Parent organism divides into two divides into two

• approximately approximately equal parts. Each equal parts. Each daughter cell daughter cell becomes a new becomes a new individual.individual.

Binary Fission

BacteriaBacteria

• BacteriaBacteria– No organized nucleus.No organized nucleus.– Genetic material in the form a single Genetic material in the form a single

circular chromosome. circular chromosome. – Before division starts chromosome is Before division starts chromosome is

replicated then each daughter cell replicated then each daughter cell gets one copy of the chromosome.gets one copy of the chromosome.

– Can occur every 20-min.Can occur every 20-min.

ProtozoanProtozoan

• Protozoa Protozoa – Mitosis occurs. – Mitosis occurs. CytoplasmCytoplasm

pinches in and divides the pinches in and divides the organism in half. Each half has a organism in half. Each half has a copy of the genetic material. copy of the genetic material. Diagram.Diagram.

• Protozoa Protozoa – Mitosis occurs. – Mitosis occurs. CytoplasmCytoplasm

pinches in and divides the pinches in and divides the organism in half. Each half has a organism in half. Each half has a copy of the genetic material. copy of the genetic material. Diagram.Diagram.

They Where best budsThey Where best buds

• BuddingBudding = Parent organism = Parent organism divides into two unequal parts. divides into two unequal parts.

• The new organism is created as a The new organism is created as a smaller out growth or bud on the smaller out growth or bud on the outside of the parent.outside of the parent.

• Buds will brake off and live Buds will brake off and live independently or remain independently or remain attached and form a colony.attached and form a colony.

Budding

• Yeast Yeast – Once the yeast cell – Once the yeast cell reaches a certain size it reaches a certain size it undergoes mitosis. undergoes mitosis.

•Once the genetic material is replicated Once the genetic material is replicated budding begins.budding begins.

• HydraHydra – Cells on the outside of the – Cells on the outside of the parent hydra begin to undergo parent hydra begin to undergo mitotic division creating a small mitotic division creating a small group of cells. Those cells group of cells. Those cells continue to divide until in a continue to divide until in a completely new hydra is formed. completely new hydra is formed. Can also reproduce sexually.Can also reproduce sexually.

• Yeast cell cycle including budding:Yeast cell cycle including budding:

• http://brodylab.eng.uci.edu/cgi-bin/jphttp://brodylab.eng.uci.edu/cgi-bin/jpbrody/animation/files/13-977277560.brody/animation/files/13-977277560.htmlhtml

Can I have some spore?Can I have some spore?

• Spore FormationSpore Formation – spores = small – spores = small specialized cells that contain a specialized cells that contain a nucleus and cytoplasm surrounded nucleus and cytoplasm surrounded by a thick outside wall which by a thick outside wall which protects the spore. Under the right protects the spore. Under the right conditions the spore can rise to a conditions the spore can rise to a new organism. Found in bacteria, new organism. Found in bacteria, molds, yeast, mushrooms, mosses, molds, yeast, mushrooms, mosses, ferns and some protozoans.ferns and some protozoans.

Spore formation

Don’t try this at homeDon’t try this at home

• RegenerationRegeneration = The ability to re- = The ability to re-grow lost or damaged body parts. grow lost or damaged body parts. Hydra, planaria, starfish, and Hydra, planaria, starfish, and earthworm More complex animals earthworm More complex animals less able to re-grow parts. Crab can less able to re-grow parts. Crab can re-grow a claw. Some reptiles can re-grow a claw. Some reptiles can re-grow a tail. Most mammals can re-grow a tail. Most mammals can repair damaged tissue but can not repair damaged tissue but can not re-grow missing parts.re-grow missing parts.

Regeneration

Vegetative Vegetative ReproductionReproduction

• Bulb Bulb = Short = Short underground underground stem surrounded stem surrounded by thick leaves. by thick leaves. Contain stored Contain stored food. As the food. As the plant grows it plant grows it produces new produces new bulbs which will bulbs which will grow into new grow into new plants. Tulips, plants. Tulips, onions, and onions, and lilies.lilies.

• CormsCorms = = Similar Similar to bulbs to bulbs but do but do not not contain contain leaves, leaves, just just undergrunderground ound stems. stems. Water Water chestnutchestnuts.s.

• Tuber Tuber = = enlarged part enlarged part of an of an underground underground stem that stem that contains stored contains stored food. Potatoes food. Potatoes are tubers. are tubers. “Eyes” = tiny “Eyes” = tiny buds that can buds that can form a new form a new potato plant. potato plant. How you plant How you plant potatoes. potatoes. Great potato Great potato famine.famine.

• Runner or stolenRunner or stolen = horizontal stem = horizontal stem above the ground above the ground with buds. If a with buds. If a bud touches the bud touches the ground it will form ground it will form roots and stems roots and stems and start a new and start a new plant. plant. Strawberries.Strawberries.

• RhizomeRhizome = = horizontal stem horizontal stem that grows that grows underground. underground. Thick and Thick and contains stored contains stored food. Upper food. Upper portion form portion form nodes which nodes which will form buds will form buds which will form which will form new plants. new plants. Lower portion Lower portion forms roots. forms roots. Ferns, cattails, Ferns, cattails, and water lilies.and water lilies.

Artificial Vegetative Artificial Vegetative ReproductionReproduction

Watch out for those old Watch out for those old ladies.ladies.

• Cutting Cutting = use a = use a portion of a portion of a developed plant to developed plant to make a new plant. make a new plant. Roses, ivy, and Roses, ivy, and grapevines are grapevines are reproduced in this reproduced in this way.way.

• LayeringLayering = a stem = a stem is bent so that it is is bent so that it is covered with soil. covered with soil. Once the branch Once the branch forms roots it is forms roots it is disconnected from disconnected from the original plant. the original plant. Raspberries and Raspberries and roses.roses.

• GraftingGrafting = Bud or = Bud or stem of one plant stem of one plant is permanently is permanently attached to the attached to the stem or trunk of stem or trunk of a very similar a very similar plant. The plant. The cambium layers cambium layers grow together grow together and form a single and form a single plant. Apple plant. Apple trees.trees.

That’s a strange cactiThat’s a strange cacti

Why Bother??Why Bother??

• Advantages to artificial vegetative Advantages to artificial vegetative propagation:propagation:

1. Plants that grow from seed are not 1. Plants that grow from seed are not always exactly the same as their parents.always exactly the same as their parents.

2. Takes less time to artificially propagate.2. Takes less time to artificially propagate.

3. Can create seedless fruits.3. Can create seedless fruits.

4. Grafting can be used to generate higher 4. Grafting can be used to generate higher levels of fruit and nut production.levels of fruit and nut production.

Can robot teachers from the Can robot teachers from the future asexual reproduce?future asexual reproduce?

(Relax that was a rhetorical question)

WebsitesWebsites

• Yeast cell cycle including budding:Yeast cell cycle including budding:• http://brodylab.eng.uci.edu/cgi-bin/jphttp://brodylab.eng.uci.edu/cgi-bin/jp

brody/animation/files/13-977277560.brody/animation/files/13-977277560.htmlhtml

• Mitosis animation:Mitosis animation:• http://brodylab.eng.uci.edu/cgi-bin/jphttp://brodylab.eng.uci.edu/cgi-bin/jp

brody/animation/files/6-973887139.hbrody/animation/files/6-973887139.htmltml