5. All living things need food to survive.
Animals are dependent on plants for food, shelter and
oxygen while green plants make their own food.
How do
plants make
their own
food?
6. LEAF
• Leaves are flat blade like structures that are attached to the stem.
They prepare food for the plant. So, they are called the
food factory of the plant.
• Plants breathe through small openings on their leaves called stomata.
Carbon dioxide is absorbed through this stomata.
• All leaves are green due to the presence of a green pigment in the
leaf called chlorophyll.
7. Food for Plants (Green Plants)
Plants
(Producers)
FOOD (Sugar or glucose)
(Leaves)
sunlight
water and
minerals
carbon-di-
oxide
PHOTOSYNTHESIS
Photo – light,
synthesis – putting together
stomata
8. Photosynthesis
Green plants absorb energy from the sun. This energy is absorbed with the help
of a pigment called chlorophyll, which is present in all the leaves.
Water and minerals are absorbed by the roots and are carried to the other parts
of the plant.
Carbon-di-oxide is absorbed through tiny pores in the leaves called stomata.
Water and minerals
9. Carbon-di-oxide + water Sugar + oxygen
Sunlight, water and carbon-di-oxide are used to make food in the
form of glucose or sugar and oxygen is released into the air.
sunlight
chlorophyll
A portion of glucose is used by plants for their growth. The remaining glucose is
stored as starch in different parts of the plants such as roots, stems, leaves, seeds
and fruits. Some vegetables like potato and tapioca are rich in starch.
10. Extended Learning
Have you seen these kind of leaves?
Why are they in different colours?
How do they prepare food for them without chlorophyll?
Yellow-Orange colour is due to the presence of a pigment called Carotenoids.
Red or purple colour is due to the presence of a pigment called Anthocyanins.
The large amount of red, yellow
and purple pigment mask the
green colour of chlorophyll in
these leaves. But still
chlorophyll is present in small
amount.
11. Extended Learning
Do you know how the animals who eat only leaves are called?
They are called folivores.
E.g.: koala bears, giraffes, caterpillars etc.
Which tree has the longest leaf in the world?
Raphia regalis, a species belonging to the
palm tree.
13. Home Fun
Question Time!
1. ____________ is the food factory of a plant. (stem / leaf)
2. What do plants need for photosynthesis?
3. Name the pigment which is present in the leaves. (chlorophyll / stomata)
4. The gas which is absorbed through the stomata of leaves – (Oxygen / carbon dioxide)
5. The pigment which is present in yellow coloured leaves – (Carotenoids / Anthocyanins)
6. Name a folivore - ____________
Place a healthy, growing, leafy plant by the window for three days. Take a tape and cover it over some of the
leaves. After three days, remove the tape and observe the colour. Take a picture, write your observation and
send it to me.
14. Parasitic Plants
Plants obtain nutrients from the soil. Overtime these nutrients run out and need to be
replaced. This is why gardeners add manure and fertilizers in the soil.
Plants that obtain nutrition by growing on other plants are called parasitic plants. The
plants on which the parasitic plants feed are called host plants.
Host plant
Parasitic plant
15. Parasitic plants attach themselves firmly to the stems or
roots of the host plant to absorb nutrients.
E.g. Mistletoe, dodder or cuscuta.
Non-green plants like mushroom, mosses and some fungi
depend on other plants for food.
16. Epiphytes
They are plants that grow on another plant or an object for physical
support.
E.g. Orchids, ferns and mosses.
17. Carnivorous or Insectivorous Plants
Plants that obtain nutrition by eating small animals such as insects, flies and bugs are
called carnivorous or insectivorous plants. They grow in soil and lacks certain
nutrients like nitrogen. They trap insects to get nitrogen. However, all carnivorous
plants derive energy from the sun and depend on animals for nutrition. Carnivorous
plants digest their prey using enzymes.
E.g. Pitcher plant, sundew and Venus fly trap.
Sun dew plants have a gel-like sticky
substance that covers the leaf. Insects
easily get stuck to the plant and become
prey.
18.
19. Carnivorous or Insectivorous Plants
Sun dew plants have a gel-like sticky
substance that covers the leaf. Insects
easily get stuck to the plant and become
prey.
20.
21. The Venus fly trap has jaw like leaves with spiky teeth
along the edges. As soon as an insect sits on the leaf,
the leaf closes and traps it.
22.
23. A pitcher plant looks like a pitcher with a lid. It has hair and
nectar inside that attracts insects. As soon as an insect sits on
it, the lid closes, thus trapping the insect.
24. New Words
Video link: https://www.youtube.com/watch?v=4yvUjwt2-jI&t=57s
:
chlorophyll parasitic carnivorous
insectivorous enzyme pitcher
stomata pitcher photosynthesis
25. Food for Animals
All animals are consumers as they depend on plants as well
as animals for food.
Plants – Producers
Animals – Consumers
Based on the kind of food they eat, animals are classified as:
Animals who feed on only plants. E.g. cows, deer,
elephants, goat etc.
Animals who feed on other animals. They indirectly
depend on plants for their food. E.g. lions, tigers,
leopards etc.
Animals who feed on both plants and animals. E.g.
crows, cockroaches, bear etc.
26. The animals who help us to keep the environment
clean by eating dead animals. E.g. Hyenas, vultures,
crows etc.
The organisms that obtain their food by consuming
dead and decaying plants and animals. E.g. Bacteria,
fungi and earthworms.
All dead plants and animals are recycled in nature by the
decomposers that help to release nutrients from them
into the soil, which are then used by the plants for
nutrition.
27. Interdependence
It is the dependence of two or more living organisms
on each other.
Plants and animals depend on each other for various needs.
Plants depend on animals for carbon-di-oxide, insects such as bees
and birds help in seed dispersal and earthworms help to make the
soil fertile for plant growth.
28. Animals and human beings depend on plants for food and
oxygen.
Some animals depend on plants for shelter.
Human beings also depend on plants for other needs such as
clothes and medicines. Plants are sources of non-renewable
resources like coal, petroleum and wood.
29. New Words
Video link: :https://www.youtube.com/watch?v=4-zRIZlpih8
consumers herbivores carnivores
omnivores scavengers decomposers
interdependence bacteria fungi
30. Food chain
It is the chain formed when plants are eaten by animals and then these
animals are eaten by other animals.
Food chains show how energy is passed form the sun to producers, from
producers to consumers and from consumers to decomposers. Plants are
eaten by herbivores, which in turn are eaten by carnivores.
Sun producers consumers decomposers
31. Food chain on land
A rabbit eating grass is an example of a simple food chain
32. Food chain in water
In pond or a river, the food chain starts with aquatic plants such as algae
because they are producers. Snails feed on algae and are then eaten by fish.
Fish are eaten by cranes.
algae snail fish crane
33. Food web
A food chain does not exist independently in nature. Different interconnected
food chains form a food web. Organisms of one food chain can be eaten by
different organisms of another food chain.
Plants are eaten by herbivores such as grasshoppers, rabbits and deer.
Herbivores are eaten by many carnivores such as tigers, lions and wolves. In the
same way, lions can eat deer, rabbits, zebras and cows.
34. Food chains and food webs maintain a natural balance in the population
of living things on the Earth. Animals, plants, birds and marine species
are as important as human beings. If the population of one organism
increases or decreases, the entire food chain gets disturbed.
35. Extinction of Living Organisms
All living organisms on the Earth have a unique place in the food chain that helps
them contribute to the ecosystem. An ecosystem is a community of interacting
organisms and their physical environment. However, many animals, plants are
endangered. An endangered species is an animal or plant species that is danger
of becoming extinct, that is, its number is decreasing rapidly. This happens
because of an increase in the number of predators, climate change or loss of
natural habitat.
Video Link: https://www.youtube.com/watch?v=RBdLF0JlvW8
