1. Sec. 5.2 – Asexual Reproduction
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5.2 Asexual Reproduction
Produces clones = identical genetic copies of the parent
Many organisms naturally form clones by asexual reproduction
Also used in agriculture & research to copy desired organisms, tissues and genes
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Types of Asexual Reproduction
Binary fission - single cell organisms splitting into identical copies
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Budding - a new organism develops from an outgrowth (“bud”) due to cell division at one particular site.
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Fragmentation - part of an organism breaks off due to injury, and the part grows into a clone of the parent
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6. Vegetative reproduction - special cells in plants that develop into structures (ex. stolons, rhizomes, etc.) that form new plants
Spore formation - some bacteria, micro-organisms and fungi can form spores - single cells that can grow into a whole new organism

7. Advantages to Asexual Reproduction
Only need one parent
No time needed to find mate
Less energy required because no mate to find
No gametes (egg/sperm) needed
Can create a large number of offspring quickly
Large colonies can out-compete other organisms for resources
Large colonies may survive changing conditions & predation better
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8. Disadvantages to Asexual Reproduction
Offspring are clones
would all inherit bad traits
would all be susceptible to same diseases
no variation to allow survival if conditions change dramatically
if colonies are close together, they could compete for resources
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9. Human Assisted Cloning
A.k.a. Artificial selection
Used to produce desired traits within an organism
We use all asexual reproductive methods
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Examples:
Reproductive cloning - used to produce a genetic duplicate of an existing or dead organism.
Steps involved:
Remove nucleus from an egg cell
A mammary gland cell is removed from an adult female
Electricity fuses mammary and egg cell
Fused cell begins dividing
Dividing embryo is inserted into surrogate mother
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12. Issues Only about 10% of clones survive
Surviving clones can be abnormally large & have higher risk of infection and cancer
Ex) Dolly only lived 6 years and died of lung disease
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13. Therapeutic cloning - purpose is to correct health problems
Uses stem cells - cells that can become different types of cells
Stem cells can replace cells damaged from injuries or disease
Controversial because the best stem cells are embryotic
However, many diseases are now treated with adult stem cells
Diabetes, spinal injuries, Parkinson’s disease, cancer
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15. Autologous Stem Cell Rescue
Take the Section 5.2 Quiz