Chapter 10: Asexual Reproduction

Advantages
1. Growth can occur very rapidly;
  1. Hence can rebuild their numbers rapidly
  2. Can produce twice as fast the rate of sexually reproducing organisms
2. Every member of a population can give birth too offspring; in sexual R. only females can give birth
3. Can quickly exploit the resources of space and energy in this new habitat if a new habitat becomes available for colonisation.
4. Organisms with a successful genetic makeup (genotype) can spread quickly
  1. Parental genotype is passed on unaltered because it does NOT involve the process of genetic shuffling
Disadvantages
1. Does not create any genetic variability
  1. Likewise if a disease breaks out, it could affect all members
  2. If one member of the population is susceptible, all will be susceptible
  3. Genetic uniformity reduces the change of a population adapting to new environmental conditions
2. Rapid population growth may lead to competition for resources such as food, shelter and nesting sites
Key Concepts
1. The daughter cells are CLONES, hence no genetic variability
2. Does nor involve GAMETES
3. In prokaryotes: involves binary fission. In eukaryotes: involves mitosis
Technology: Asexual Reproduction
1. Issues concerning cloning
  1. Somatic cell cloning is very unreliable; with fewer than 1 percent of cloned embryos surviving beyond birth. Of the clones that do survive beyond birth, many have abnormalities that result i an early death
Definition: A form of reproduction in which one parent produces offspring that are genetically identical to each other and of the parent
Examples of asexual respoduction
1. Prokaryotes
  1. Binary Fission
2. Eukaryotes
  1. Binary Fission (splitting)
    1. Examples: Flatworms, amoeba, anemones
    2. Occurs in unicellular organisms only, because the structure of multicellular is too complex, being built of different tissues and organs
    3. They split in two like bacteria, however, involve the process of mitosis
  2. Budding
    1. Clone of parent is produced. Bud grows out of parent and detaches for form a new organism
    2. Examples: Sea sponges, jelly fish
  3. Spitting/Fregmentation
    1. The body of the parent organism splits into two or mre pieces. Each piece regenerates the missing pieces
    2. Examples: Flat worms,sponges
  4. Spore Formation
    1. Examples: Mushrooms, algae, mold, toad stools
    2. Offsprings are NOT clones of parents. Spores which are haploid are released from a structure called sporangia. Spores disperse and grow to become new organism
  5. Vegetative Reproduction
    1. Where organ parts of a plant can give rise to new off springs that are genetic of the parent
    2. Examples: All types of plants that contain bulbs, stems, runners, rhyzomes
  6. Parthenogenisis
    1. Offspirngs are produced from unfertilised eggsby mitosis and develop into offspring identical to female parent
    2. Examples: Many invertibrate animals but also whiptail lizards and some shark species

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Chapter 10: Asexual Reproduction

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