SCIENCE CA
REVISION
TOPICS:
1. GROWING THINGS USING HYDROPONICS
2. TYPES OF SEED DISPERSAL
Two type of plants
Normal plants grow in soil, but hydroponic plants grow in water with nutrients
Needs of a soil grown plant
Needs of Hydroponics plant
.
Needs of Hydroponic Plants:
1. Water - Instead of soil, hydroponic plants grow in water.
The water gives them what they need.
2. Nutrients - Nutrients are added to the water to help the
plants grow.
3. Sunlight - They need sunlight or special lights to grow.
4. Air - Hydroponic plants also need air to grow strong
roots.
5. Support - Since there is no soil, plants might need
something like cotton or sponges to hold their roots.
Activity: Draw a hydroponic plant .
Leaves
Stem
Air
Roots
WAYS OF SEED DISPERSAL
Wind Dispersal: Some seeds are carried by the wind. Seeds float in the air.
Example: Dandelion seeds.
Water Dispersal: Some seeds float on water and travel to new places. Example:
Coconut seeds float in the ocean.
Animal Dispersal: Animals can carry seeds in their fur, feathers, or on their
bodies. Sometimes, animals eat the seeds and later drop them in a new spot.
Example: Burrs stick to animals' fur, and then they drop off when the animal
moves.
Explosion Dispersal: Some plants “explode” and fling their seeds far away.
Example: Peas or poppy plants.
Human Dispersal: People also help spread seeds when they plant flowers, trees,
or crops, or even if seeds get stuck on shoes or clothes!
KEY WORDS
Carry away
Floating
Falling
Exploding
Burst
Shaking
Scattering
Sticking
Dropping