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Name: James
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Question:
How do asexual organisms reproduce and how do they evolve?



Replies:
Asexual organisms reproduce by fission (splitting in half) or by budding (a small piece buds off the parent cell and then grows to the adult size. The two new cells are clones of each other-ie. they contain identical genetic material. One way for these organisms to evolve is by mutations, or mistakes in their DNA. Bacteria have evolved ways of passing genetic material back and forth however. Sometimes this is called "bacterial sex", although it is not for sexual reasons. In the process of conjugation, one bacteria sends out a tube called a pillus that attaches to another bacteria. Small circular pieces of extra DNA called plasmids are sent through the tube. These plasmids usually contain genes that will allow the bacterium to survive adverse environmental conditions. Some genes include antibiotic resistance genes. New genes are sometimes transferred from one bacterium to another by a virus in a process called transduction. The virus accidentally takes a few genes with it from the host when it infects a new host. Lastly, some bacteria can take up DNA from the surroundings when other bacteria die and break apart. This is known as transformation.

Van Hoeck



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