Subject Environmental Sciences in the syllabus of 1st year b pharmacy semester 2nd contain point The FOOD CHAIN & FOOD WEB.

1. Food Chains and
Food Webs
B. Pharmacy, Sem-II
Subject- Environmental Sciences
Presented by- Assist. Prof. Shubhangi Sonawane.
SVPM’s College of Pharmacy
Malegaon (Bk)- 413115

2. Consumers
Consumers
Producers Decomposers
Secondary
Consumers
• A single pathway showing the feeding
relationships between organisms
• Shows the transfer of matter and
energy in an ecosystem
Who Eats Who?
Primary
Consumers
Herbivores Carnivores or
Omnivores

3. Food Chain
• A food chain refers to the order of events in an ecosystem, linear
sequence where one living organism eats another organism, and later
that organism is consumed by another larger organism. The flow of
nutrients and energy from one organism to another at different trophic
levels forms a food chain.
• The food chain also explains the feeding pattern or relationship between
living organisms. Trophic level refers to the sequential stages in a food
chain, starting with producers at the bottom, followed by primary,
secondary and tertiary consumers. Every level in a food chain is known
as a trophic level.
owl

5. Types of Food Chain
1) Grazing food-chain:
• In a grazing food-chain, the first level starts with plants as
producers and ends with carnivores as consumers at the last level,
with the herbivores being at the intermediate level.
• There is a loss of energy at each level which may be through
respiration, excretion or decomposition.
• The levels involved in a food chain range from three to five and
energy is lost at each level.
• The grasses →rabbit →Fox sequences
• are the examples, of grazing food chain.

6. Types of Food Chain
2. Detritus food chain:
• This type of food chain goes from dead organic matter into
microorganisms and then to organisms feeding on detritus
(detrivores) and their predators.
• Such ecosystems are thus less dependent on direct solar energy.
• These depend chiefly on the influx of organic matter produced in
another system.
• For example, such type of food chain operates in the decomposing
accumulated litter in a temperate forest.

7. Parts of Food Chain
PRODUCERS
• They make their own
food through a process
called photosynthesis.
• They use sunlight, water
and carbon dioxide to
produce food.
eucalyptus trees spinifex grass

8. Parts of Food Chain
CONSUMERS
• They cannot make their
own food.
• They get their energy
from eating plants and
other animals.
koala dingoes

9. Parts of Food Chain
DECOMPOSERS
• They break down dead
plants and animals into
simpler substances and
recycle nutrients into the
soil.
• They serve as a 'cleanup
crew'. fungi termites

10. Summary
Food Chain Producers Consumers Decomposers
It shows the
transfer of
matter and
energy in an
ecosystem.
They make
their own
food through
photosynthesis.
They feed on
plants and
other animals
to survive.
They break down
dead plants and
animals into simpler
substances and
recycle nutrients
into the soil.

11. THE FOOD WEBS
• Food Web is a network of food chains due to interlinking with each
other at several points in a biotic community.
• Under natural conditions, food chains remain indeed interconnected
with each other through different types of organisms at different trophic
levels.
• Normally a food web operates according to taste and food preferences of
the organisms. Other factors like availability of food source are equally
important, e.g., tigers of Sunder bans eat fish and crab in absence of
their natural preys. Wild cats prey upon mice as well as squirrels and
birds. Snakes feed upon mice (herbivores) as well as frogs (carnivores).

12. THE FOOD WEBS
Key Points
Organisms can be organized into trophic levels: primary producer, primary
consumer, secondary consumer, and tertiary or higher-order consumer.
Energy decreases in each successive trophic level, preventing more than
four or five levels in a food chain.
An ecosystem usually has two different types of food webs: a grazing food
web based on photosynthetic plants or algae, along with a detrital food
web based on decomposers (such as fungi).
There are different types of food webs including grazing food webs based
on photosynthetic plants (such as algae) or detrital food webs based on
decomposers (such as fungi).

17. THANK
YOU
B. Pharmacy, Sem-II
Subject- Environmental Sciences
Presented by- Assist. Prof. Shubhangi Sonawane.
SVPM’s College of Pharmacy
Malegaon (Bk)- 413115