Transcript Our Precious Environment

Our Precious Environment
How do animals and plants grow?
• Plants and animals need air, water, light and
nutrition to grow.
• Green plants uses Photosynthesis process to
create energy for survival and growth.
• Since plants create their own energy, they are
the first link in the food chain.
• Animals need to drink water and eat plants and
other animals to get energy.
• So animal are in the nest steps in the food chain.
How do plants get food
• Plants produce their own food except few
pants which eats other organism.
• Green plants use water, nutrient and
chlorophyll to produce their food.
• Mainly water and nutrients are absorbed
from the ground through their roots. Some
plants, however, have developed other
methods.
How do plants get food
What happens to plants if there is
no light?
• In absence of light, plants shed their
leaves and die, leaving only their roots and
stem.
What is photosynthesis
• Photosynthesis occurs in chloroplast inside
green leaves.
• water (HO) is supplied through roots into leaves
• Carbon dioxide (CO₂) is absorbed from air into
leaves.
• Both these are broken down into 3 elements–
Hydrogen(H), Carbon (C) and Oxygen(O) with
help of chlorophyll and sunlight.
• Thus, plants build glucose and releases oxygen.
What is photosynthesis
What is the food chain
• Plants develop energy through
photosynthesis.
• They are eaten by a consumer.
• That consumer is often eaten by another
consumer.
• This called food chain.
• For example– grass-cow-man.
What is the food chain
Broad classification of plants
Plants can broadly divided into 2 divisions—
• Plants with chlorophyll
• Plant without chlorophyll
Are bacteria and viruses plants or
animals?
• Bacteria are single-cell organism without
the cell nucleus.
• Viruses are only nucleic acid molecules.
So they are neither animals nor plants
because
Animals are multicellular organisms.
Plants always have nucleus.
bacteria and viruses
• Bacteria
• Viruses
How do plants reproduce
Plants reproduce in various ways—
• Many species build side shoots, from
which plats grow.
• Plants like mosses and ferns reproduce
with the help of spore, which are
distributed by wind and grow to become
new plants.
How do plants reproduce
• Plants with seed, has male and female
organ. The male organ has pollen. These
pollen sticks to the stigma and is passed
onto the egg cell in the ovary. A fertilized
egg ripens to become fruit. Theses fruits
have seeds. When seeds are dispersed on
soil, they again becomes plants or trees.
How do plants reproduce
Different types of soils
1. Soil Type: Sandy
• Sandy soil has the largest particles among
the different soil types.
• It is dry and gritty to the touch,
• Because the particles have huge spaces
between them, it can’t hold on to water.
Different types of soils
• Sandy Soil
Different types of soils
2. Soil Type: Silty
• Silty soil has much smaller particles
than sandy soil so it’s smooth to the
touch.
• When moistened, it’s soapy slick.
• Silty soil retains water longer, but it
can’t hold on to as much nutrients
• Silty soil is cold.
Different types of soils
Soil Type: Silty
Different types of soils
3. Soil Type: Clay
• Clay soil has the smallest particles
among.
• It has good water storage qualities.
• little air passes through its spaces.
• Because it is also slower to drain, it has
a tighter hold on plant nutrients.
• Clay soil is thus rich in plant food for
better growth.
Different types of soils
Clay