Koshi High School Kumi Ikeda Nao Ito Nodoka Uchida Hayato Ohata The difference in the growth of algae in the presence or absence of sunlight Koshi High School 　　　　　 Kumi Ikeda 　　　　　 Nao Ito 　　　　　 Nodoka Uchida 　　　　　 Hayato Ohata

Why we chose this theme. More and more riverbeds in Japan are being covered with concrete. We thought this is bad for the environment. Are there differences in the growth of algae depending on the presence or absence of sunlight ?

The contents of our experiment. We put dechlorinated water and the same amount of algae in two water tanks.

Our hypothesis The algae with sunlight would grow better than that without sunlight.

Result shade The day we started our experiment. Sunlight

Result shade One week later… Sunlight

Result shade Two weeks later… Sunlight

Result shade Three weeks later… Sunlight

Consideration Sunlight

Consideration shade

Consideration Sunlight

Consideration shade

The types of the two water tanks were not the same. This may have affected the result to some extent.

Further research We are going to see if there are some differences in the photosynthetic pigment in algae from the river.

Procedure ①Grind the material with a mortar and 　　pestle and add acetone to extract pigments.

Procedure ②Separate the pigments using paper chromatography.

Paper chromatography

Paper chromatography Water

Paper chromatography

Procedure ③Try to find the Rh value based on the formula. Rh value= Movement distance of the pigment⟨㎝⟩ Movement distance of the liquid which unfolded⟨㎝⟩

A bibliography ○光合成色素の分離　http://www.makasaka.net/seibutu/chromato/chromato.html

Thank you for listening.