Irritation

TASK 1: Chemotaxis in ciliates

NP: hay infusion

Put two drops of hay infusion onto the slide (do not cover). Connect both drops using skewer to form a thin bridge. Then add several crystals of salt (NaCl) to one of the drops. Observe negative chemotaxis.

fig.

TASK 2: Oxygenotaxis in ciliates

NP: hay infusion

Cover a drop of hay infusion with cover glass and form air bubbles under it. You can observe positive oxygenotaxis. The same effect can be observed at the edges of cover glass.

fig.