LESSON 1: STRUCTURES AND
FUNCTIONS OF PLANTS
LESSON 1:
Adaptation
Response
Stimulus
Transpiration
Tropism
Explain how
plants use their
structures to
survive, grow
and reproduce.
Activity one:
Plant needs:
• What do you think a plant
needs to live and survive?
• Air : The air around Earth is a
mixture of gases.
• Plants need one of these
gases, carbon dioxide, to
make food.
• Sunlight
• Plants need sunlight to make
food.
• They use sunlight to make
sugar.
• Plants use their leaves to
gather sunlight.
• Water:
• All living things need
water.
• Water used by plants also
to make food and provide
support.
• Plants take water by roots
 Stem.
• Nutrients:
• Living things need it to
stay healthy.
• Most nutrients
dissolved with water
and absorbed by
roots.
• Space: Plants need
enough space to get the
air, water, sunlight, and
nutrients.
• Crowded plants face
difficulties to get their
needs.
Lets check
• What are the
plants needs?
Plant parts
• Roots:
• Take water and
nutrients
• Hold the plant
• Some roots store food.
• Stem Support the plant, and
part of transport system.
• Two types:
•  Soft stem: green and
flexible
•  Woody stem: hard and
covered with bark
• Leaves:
• Vary in shape and size.
• Most have line of
symmetry.
• Site of gas exchange and
food production
• Transpiration:
• Release of water vapor
from the leaves or
sweating of the plant,
through Small pores or
openings called
stomata.
Lets check
• Identify the
parts of plant
and each one
role?
• Reproduction in plants:
• A. Flowers:
• Male  stamen  anther
 produce pollen
• Female  pistil  ovary
 produce egg
•  Insects, birds and wind
help transfer the pollen.
Pollination & Fertilization
Fertilization occur when
pollen joins the egg inside
the ovary and seeds will
produced.
Pollen + egg  fertilization
 seeds
• Cones: Some seed plants
reproduce by cones.
• 1. Male cone  pollen 
released to wind
• 2. Female cone  sticky
liquid take the pollen 
fertilization happens here
• Adaptation is a physical trait
or behavior that help an
organism to survive.
• Plants can adapt either for
protection or to find food.
• Cactus have thick waxy stem
store water
• Flowers have thorns for
protection.
• Some plants produce
chemicals.
• Change in environment
that cause the organism
to respond is called
stimulus.
• The reaction of this
organism is called
response.
• Response to water, sun or
gravity is called tropism.
• Phototropism  light
• Gravitropism  gravity
• Thigmotropism  touch
• Hydrotropism  water
Lets check: Identify kinds of tropism!