Asexual Reproduction

Asexual Reproduction

Definition of Reproduction

The process by which living organisms produce new organisms of their own kind

Two types of Reproduction

SexualAsexual

Asexual ReproductionA single parent produces an identical

offspringSame hereditary information (genes) in

the offspring as in the parentSame traits generation after generationProcess happens quickly and produces

large number of offspring

Concerns

Limited genetic variation (they are all the same) makes the organism more susceptible to mass extinction

Rapid growth may be limited by the food, water, space, etc. which may lead to death of organisms

Seven Types of Asexual Reproduction

1. Mitosis2. Binary fission3. Budding4. Spores5. Regeneration6. Vegetative propagation7. Cloning

Mitosis (#1)

Produces body cells in animals and plants

Process studied in 7th GradeCells produce an identical cell with the

same functionhttp://www.cellsalive.com/mitosis.htm

Mitosis Video

Binary Fission (#2)

Simplest form Parent cell divides

into two equal parts Example : bacteria

www.DennisKunkel.com

Amoeba

Another Example of binary fissionLive in fresh water

http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/amoeba/t1/amoeba01.htm

Amoeba engulfing (eating) food 40x

Movement

Binary Fission Video

ParameciumMany swimmersOral groove (mouth)Cilia for propulsion

http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/paramecium/index.html

Budding (#3) New individual

”grows” off parent organism

New offspring may break off or remain attached

Examples : yeast, hydra, sponges

http://micro.magnet.fsu.edu/optics/olympusmicd/galleries/moviegallery/pondscum/coelenterata/hydra/index.html

Spores (#4)

Specialized cell similar to a seed

Thick, tough outer covering

Example: fungi

Regeneration (5)Ability to re-grow lost body partsExamples : starfish, planarian,

earthworms

http://micro.magnet.fsu.edu/optics/olympusmicd/galleries/darkfield/planaria.html

Vegetative Propagation (#6)

Growing new plants from:

roots – sweet potato

stems – philodendron

leaves – african violet

Grafting Combining the roots of one plant with the

stem of another Grapes : tough wild roots + seedless (yummy)

stems Roses : tough wild roots + pretty stems 5 in 1 apple trees : roots of one tree + 5 varieties

of http://aggie-horticulture.tamu.edu/propagation/graf

tingmovies/index.html

Cloning (#7)The process of:

Scientifically-engineered reproductive technology

Removes nucleus from an egg cell Replaces it with the nucleus from a body

cell of another organism Zaps it with electricity Divides and develops into new embryo

Remove nucleus

Host Organism Sex Cell (egg)

Haploid = 1/2 chromosomes of the body

cellHuman = 23

chromosomes

Replace nucleus

Replace with a body cell nucleus

of donorblood, skin, muscle

cell* Diploid Cell

46 chromosomes

Zap with electricity

Wait 7 Days

*7 *6 *5 *4 *3 *2 *1

Place in the uterus of the host organism

9 months

*Not genetically like host

organism*Exact genetic copy of donor

cell

Offspring

CloningProcess ensures the new plant/animal

is an exact copy of the donor cell

http://www.guardian.co.uk/gall/0,8542,627251,00.html

Pictures of Cloned Animalshttp://www.guardian.co.uk/gall/

0,8542,627251,00.html

Dolly Video