Asexual Reproduction:

1
Asexual Reproduction

• It takes only one to do it!

2
What is it and whats its function?

• Asexual Reproduction is when 1 organism gives
  rise to 2 identical organisms ( this is
  essentially cloning!)
• Organisms reproduce asexually when there is an
  abundance of food, when environmental conditions
  are very good
• Asexual reproduction does not take a lot of
  energy in terms of raising the offspring or going
  through mating rituals but does allow populations
  to grow quite large in a short amount of time.

3
There are 5 types of Asexual Reproduction

• Binary Fission
• Budding
• Fragmentation
• Spore Formation
• Vegetative Reproduction

4
Binary Fission

• Virtually the same as mitosis, binary fission
  causes one cell to divide into 2 after all its
  organelles and DNA have replicated.
• Binary fission takes place in single-celled
  organisms such as bacteria and most protists

Bacteria!
Protist Paramecium
5
Budding

• http//www.yeastgenome.org/yeast_images.shtml
  from Peter Hollenhorst and Catherine Fox

• A miniature of the original parent comes off of
  the parent by an out pouching of cells or
  cytoplasm from the parent
• A new organism forms eventually and breaks away
  from the parent
• Occurs in yeast, hydra and some plants

6
Fragmentation

• Pieces from the parent break off and form a new
  organism identical to the original parent
• Occurs in planaria (a free-living flatworm) and
  sea stars.
• Often fragments of these seastars must include
  part of the middle disc to create a new organism.
• Regeneration typical in sea stars, demonstrates a
  similar mechanism in the photo here only one
  arm is being recreated.

7
Spore Formation

• When a bacterial cell senses harmful or
  inhospitable conditions, this vegetative cell
  replicates its DNA and its cell wall begins to
  surround the new DNA copy. A durable spore coat
  forms around the developing spore and eventually
  will await better conditions for growth.
• Occurs in bacteria (endospores), some protists,
  fungi, ferns and mosses.

8
Vegetative Propagation

• Stolons travel above ground and land in another
  viable place where soil is good enough that
  another crown and root system can be made
• Occurs in strawberry plants, spider plants,
  grasses, lilacs, and ferns.

9
What are the benefits to reproducing asexually?

• You dont need a partner!
• You can reproduce faster in good conditions
• You use less energy
• You increase the population of your species
• You can make an exact replica of yourself (for
  those of you who are vain!) and thus know exactly
  what the offspring will be.
• Farmers use seeds that are genetically
  identical when they plant their crops.. How does
  this benefit them?

10
What are the costs or disadvantages to
reproducing asexually?

• There is no exchange of genetic information and
  so no genetic variation will exist in the
  population evolution of a species may not occur
• Usually occurs only when environmental conditions
  are good.
• Organisms that have developed from asexual
  reproduction are prone to diseases and viruses or
  other environmental problems because of a lack of
  variability in the genetic make-up of the
  population

11
Matching Which organism would use which type of
asexual reproduction?

• ___ Yeast
• ___ Bacteria
• ___ Strawberries
• ___ Planaria
• ___ Hydra

• 1. Spore Formation
• 2. Vegetative Reproduction
• 3. Binary Fission
• 4. Budding
• 5. Fragmentation

Ans Yeast 1 3 Bacteria 1 3
Strawberries 2 Planaria 5 Hydra 4
12
Bibliography and Credits

• http//sciences.aum.edu/bi/BI2033/thomson/binaryfi
  ssion.html
• http//biology.about.com/library/weekly/aa090700a.
  htm
• http//biology.about.com/gi/dynamic/offsite.htm?si
  te
• http//www.cs.tufts.edu/7Ecabotsch/bulloughs/inve
  rtebrates/worms/flatworm.html
• http//plantphys.info/Plants_Human/vegprop/vegprop
  n.html
• http//www.microbe.org/microbes/spores.asp