Planarian Over Time Lab Report

Chloe Lindbom
Regeneration of a Planarian Over Time
Erin Davis
Biology
Mrs. Werfelman 5th Hour
10/09/2014
10/20/2014

Background: The planarian, also known as the flatworm, is a creature that live all over land, oceans, and freshwater. (Biggs, A., Gregg, K., Hagins, W., Kapicka, C., Lundgren, L., Rillero, P., 2002)
The planarian has a three­branched digestive cavity. (Alvarado, 2004) Planaria range from 1/8 to
1 inch. (Alvarado, 2004) The planarian can be cut into many pieces and each piece will grow into a new flatworm. (Alvarado, 2004) Planaria produce asexually, therefore the planarian pretty much clone themselves. (Alvarado, 2004)
The planarian has two nerve cords that run the length
For example, take 4 millimeters away from 6 millimeters for the head length and 2 millimeters away from 3 millimeters for the tail length. Then compare the two final answers to see which planarian grew the most. In the experiment the head grew more than the tail by 1 millimeter.

Analysis:
The initial length of the planarian head was 4 millimeters. The initial length of the planarian tail was 2 millimeters. By the third day the planarian was observed, the planarian head grew 1 millimeter while the planarian tail stayed at 2 millimeters. On the fifth day the planarian was observed the planarian head grew another millimeter and the planarian tail grew 1 millimeter.
The last day the planarian was observed the planarian head was the same length at 6
Overall, the planarian head grew 2 millimeters and the planarian tail grew 1 millimeter. The average growth rate for the planarian head was ⅓ millimeter per observation day. The average growth for the planarian tail was ⅙ per observation day. Conclusion:
If the planarian is horizontally cut in half, then the planarian’s head will generate the most.
Before the experiment the planarian head was thought to grow more than the planarian tail.
After the experiment the planarian head ended up growing more than the planarian tail. The hypothesis for the experiment was supported by the data. Over the observation days the planarian head seemed to have a more rapid growth than the planarian tail. Table 1 shows that the planarian head started to grow on the seventh day of the experiment while the planarian tail started to grow on the ninth. As seen in Table 1, over the course of 6 observation days the planarian head grew 1 millimeter more than the planarian tail. Based on the hypothesis before the experiment started, the planarian head was thought to grow more than 2 millimeters overall.
The planarian tail grew 1 millimeter overall concluding that planarian head grew the