Chapter 3 Lessons 5 & 6

*Plant Responses, Growth, & Import

*What are the stimuli that

produce plant

responses?

1. Tropism – a plant’s growth in response to a stimulus*Positive tropism – growth is toward the

stimulus*Ex. Plant growing toward the light

(phototropism)*Negative tropism – growth is away from the

stimulus*Ex. Plant growing away from gravity

(gravitropism)

*How do plants respond to Seasonal

Changes?

1. Photoperiodism*Short day plants – flower when the days are

short*Long day plants – flower when the days are

long2. Dormancy*Helps plants survive freezing temperatures

and the lack of liquid water*Ex. Deciduous trees – drop their leaves

*How are plants important to everyday

life?

1. Environment*Habitats for animals, food, oxygen, clean

water, hold soil in place

2. Humans*Food, clothing, building materials, fuel