Transcript Plant Responses and Growth

Plant Responses and Growth
EQ: How do plants respond to
stimuli and hormones?
EQ: How do plants
respond to stimuli and
hormones?
Tropisms
• A plant’s growth response toward or away
from a stimulus
– Thigmotropism - Touch
– Phototropism - Light
– Gravitropism - Gravity
Positive Tropism
• A plant growing toward a stimulus
EQ: How do plants respond to
stimuli and hormones?
Negative Tropism
• A plant growing away from a stimulus
http://plantsinmotion.bio.indiana.edu
/plantmotion/movements/tropism/gra
vitropism/gravi1/gravitrop.html
EQ: How do plants respond to
stimuli and hormones?
Plant Hormones
• Hormone – a chemical that affects how a
plant grows and develops
– Control tropisms
– Germination
– Formation of plant parts
– Shedding of leaves
– Development of fruit
EQ: How do plants
respond to stimuli and
hormones?
• Auxin –
– Speeds up
plant
growth
– Controls
plant’s
response
to light
EQ: How do
plants respond
to stimuli and
hormones?
Plant Hormones
Life Spans of Angiosperms
• Annuals – flowering plants that grow,
flower and die in a single year
• Biennials – complete life cycle in two years
– 1st year germinate, grow roots and very short
stems and leaves
– 2nd year grow new stems and leaves, produce
fruit
• Perennials – live longer than two years
EQ: How do plants respond to stimuli and
hormones?
Class Work and Homework
• Fill In
– What did I learn
– Confused
– Say
Read pages A164 – A166
Questions 1-4 A 166
EQ: How do
plants respond
to stimuli and
hormones?