chemotaxis of slime mold plasmodium...in high school biology on chemotaxis of slime mold plasmodium....

Chemotaxis of slime mold plasmodium

Toyota Nishi High SchoolRepresentative students

Introduction:What is Slime Mold ?


Asphalt road

Slime mold


Life cycle


plasmodium⇒Look for food

Sporangium⇒Propagating

form


Toshiyuki Nakagaki(1963~)

Professor at Hokkaido University

Graduate of Toyota Nishi High School

Cognitive Science Prize (2008)

Transportation planning Prize (2010)

Ig Nobel Prize！


Slime mold solve maze


Reproduction of road network by Slime molds


Physarum polycephalum

Experiments

Preparation

for

the Experiments

Cultivation of Slime mold

Experiment１

Observation of slime mold chemotaxis

◆Substances

・H₂O(pH7)

・NaCl(pH7)

・HCl(pH1)

・NH₃(pH11)

substance

Slime mold

Results 1:H₂O(pH7)

substancesSlime moldNeutral chemotaxis

Results 1:NaCl(pH7)

Negative chemotaxis

Results 1:HCl(pH1)

Negative chemotaxis

Results 1:NH₃(pH11)

Turned white and didn‘t move

Experiment 2

How slime molds reacted when a chemoattractant and a repellent were placed in the dish at the same time.

◆Substances

・HCl(pH1,2,3)

・NH₃(pH8)

・H₂O(pH7)

oatmeal

strings

Slime mold

Results 27cm 5cm 3cm

HCl(pH1) ◎ ○ ×

HCl(pH2) ◎ △ △

HCl(pH3) ◎ △ △

NH₃(pH8) ◎ △ △

H₂O(pH7) ◎ △ △

・◎→Went to the oatmeal ・○→Once time escaped from HCl, and went to oatmeal・△→went to the substances ・☓→couldn`t go to the oatmeal

Future View

1 Experiments using

other substances→ such as NaOH, KOH and HNO3

3 Observation of protoplasmic streaming in Slime Mold cells

2 Cultivation of slime molds on pH controlled agar medium

→ to prove the slime molds’ adaptation

Bibliography

「粘菌その驚くべき知性」Nakagaki Toshiyuki (2009), Slime Mold, Amazing Intelligence.

PHP Science World, 198pp. (in Japanese)

「粘菌はいかにして餌をみつけるか」

Abstracts of the 201* Annual meeting of Super Science High schools in Japan,

P. 212. (in Japanese)

「粘菌変形体の化学走性を利用した高校生物実験の開発」

Takahashi Kazunari (2012), Development of a classroom experiment in high school biology on chemotaxis of slime mold plasmodium.

Naturalistae (Bulletin of Okayama Science University),

No. 16, 29-38. (in Japanese)

Thank you for listening

chemotaxis of slime mold plasmodium...in high school biology on chemotaxis of slime mold plasmodium....

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