Introduction C. elegans are 1mm transparent worms used in many experiments as a model organism, since they are creatures that are easy to use and take care of in a laboratory setting. These organisms are small in size, have a short three-day life cycle, and reproduce efficiently in the lab. The C. elegans only have two sexes, male and hermaphrodite and these sexes make the organism convenient for breeding and reproduction in the laboratory environment (Hope IA, 2005). One reason the C. elegans is so highly used in experiments is that it has the ability to detect some volatile chemicals with a process called chemotaxis; this organism is shown to chemotax towards certain compounds. Chemotaxis is the gradient formed by the movement of organisms towards an odorant, also known as a substance with a certain fragrance. Odorants are that are attractive to C. elegans are usually alcohols with 4-6 consecutive carbons; any fewer or additional carbons are repellant to the worms. The substances used to dilute these alcohols are referred to as carriers. In this experiment, ethanol is used as a carrier. An example of a diluted odorant that is attractive to C. elegans is isoamyl alcohol (Bargmann, 1993). …show more content…
elegans. It was predicted that the C. elegans would be able to detect the caffeine but using chemotaxis would prefer isoamyl alcohol because of the amount of consecutive carbons. In addition to studying wild-type worms chemotaxis, mutations were also studied in this experiment. Some non-essential mutations in C. elegans have been shown to affect the rate of chemotaxis towards these diluted odorants. The mutation studied in this experiment was che-3, and it was predicted that the mutated C. elegans would not chemotaxis towards isoamyl alcohol at the same rate of the wild-type C. elegans and that both would ignore the