Tropism is a postural change toward or away from the stimulus.

1. Phototropism (response to light): observe response of Geranium plants to different light treatments.

3. Thigmotropism (response to touch): investigate response of Mimosa plant to touch. p. 198
   Write a hypothesis on p. 203: which part of plant is sensitive to touch?
   Try different stimulus types such as touching with finger or ice cube, or blowing on the leaf. Skip recovery time and graph.
   Note that each "compound leaf" is composed of several leaflets. Video:

5. We do not have time to let plants recover between stimuli.

7. SKIP drawing a graph, but do answer questions on the data sheet.

Taxis is simple orientation movement of entire organism toward or away from the stimulus.

Phototaxis in Euglena (response to light):

SKIP

Chemotaxis in Paramecium (response to chemical stimulus): p. 199

SKIP

Thigmotaxis in Brown Planaria (response to touch) p. 200

Use dissecting microscope to observe: do these flatworms respond to touch at different locations (anterior, pharynx, posterior)?

Reflexes are innate, automatic responses in animals with a nervous system.

Pupil

Blink p. 201
Suggestion: in addition to snapping fingers, do another trial tossing cotton balls at the subject wearing goggles.
(Add a row for "Cotton balls" to Table 7 on p. 207.

Knee Jerk
Subject should shut eyes and be unaware when the experimenter strikes the knee.
Suggestion: do another trial with the subject's eyes open and knowing when the strikes occur; try to suppress any knee jerk reflex.

Learning requires a complex, central nervous system.

Can you solve a line maze faster after some trials? Repeat for 10 trials. p. 202

Note: follow the lines in the maze, not the spaces: Start, Finish.