Plant Growth Development: Response to Light

This experiment in plant growth development shows that plants respond to the direction that the light is coming from which reveals plants to be responsive and far less passive than we might otherwise think. A dark box is placed over a growing seedling to see if the seedling will grow upwards or toward the light.

Materials Needed: You will need the following:

* a small plant pot and soil
* bean seeds or similar
* cardboard box
* sticky tape
* black paint and brush

The cardboard box must be large enough to accommodate the plant pot and have extra room left over for the plant to grow.

Procedure:

Step 1: Use the sticky tape to cover any gaps in the corners of the cardboard box. Holes can be easily seen by holding the box up to a strong light source. Once the box has no holes, paint both the inside and outside with black paint. Then leave the box to dry.

Step 2: Fill the pot with soil and plant at least three bean seeds in it. This is to ensure germination of at least one seed. Grow the plants until they are just showing above the soil.

Step 3: Cut a small hole, approximately 1cm in diameter, in one of the sides of the box. This will act as the light source.

Step 4: Place the black box over the growing seedling.

Step 5: Check the growth of the seedling every day. Make sure to place the box back over the seedling so that the hole is in the same position as previously.

Possible Extensions: This plant growth development experiment lends itself well to time lapse photography. If you have a digital camera or digital movie camera you could take a small amount of footage each day, then splice these together to produce a short film about the plant's growth.