FOOD CHAIN AND FOOD WEB

1. Topic
Food chain and food web
PREPARED BY
RIMSHA BAKHTAWAR RASHEED
MSC CHEMISTRY
10-5-2021

2. DIFFERENCE BETWEEN FOOD
CHAIN AND FOOD WEB.

3. • The food chain describes the feeding relationships of
different organisms in a linear fashion. This is the simplest way
of showing feeding relationships.

4. • Food web shows
multiple food chains,
relationships and
connections. This a
complicated but realistic
way of showing feeding
relationships, as most
organisms consume
more than one species
and are consumed by
more than one species.

5. Food Web Vocabulary
• Producers (autotrophs) - make their own food
• Consumers - omnivores, carnivores and herbivores that eat other plants and animals
• Decomposers - insects and bacteria that break down organisms
• Herbivores - animals that only eat plants
• Carnivores - animals that eat other animals
• Omnivores - animals that eat both plants and animals
• Trophic Level - the position of an organism on the food chain (producer, consumer, decomposer)
• Primary Consumers - the organisms that eat the plants
• Secondary Consumers - the animals that eat the primary consumers
• Tertiary Consumers - the animals that can eat both primary and secondary consumers
• Animals and Energy

6. EXAMPLES OF FOOD WEB
Food webs exist in a variety of biomes.
Because each habitat is unique, each food web is slightly different.
Explore different plants, animals and decomposers that can be found in
deserts, savannas, forests and marine environments

7. Desert
• A desert is a habitat with little water. Deserts aren't all hot either.
Some deserts are very cold. In the desert food web, you'll find:
• Producers: Cacti, bushes, acacias, flowers, brush
• Primary Consumers: Insects, lizards, rodents
• Secondary Consumers: Tarantulas, scorpions, lizards, snakes
• Tertiary Consumers: Hawks, foxes

8. In a food web, cacti are eaten
by insects, lizards or rodents.
The insects can be eaten by
the tarantulas, scorpions and
lizards. The lizards are then
hunted by snakes, foxes and
hawks. Everyone likes a little
variety in their diet.

9. Forest
• Forests have lots of trees and other plants. They are dense with lots
of different vegetation for animals to enjoy.
• Producers: Plants, fruits, nuts, seeds, flowers
• Primary Consumers: Deer, squirrels, frogs, birds, pikas
• Secondary Consumers: Pine marten, jackrabbits, ravens, ringtails
• Tertiary Consumers: Bobcats, mountain lions, coyotes

10. An example of a
forest food web
includes plants and
fruit eaten by a
mule deer. The
mule deer can then
be eaten by a lion
or bobcat.

11. Savanna
• A savanna biome has a lot of grass for animals to graze on. These
habitats are found in Africa, Australia and even South America.
Producers: Star grass, oat grass and acacia
• Primary Consumers: Grasshoppers, ants, termites, warthogs, gazelle,
impala, mice, wildebeest
• Secondary Consumers: Pangolins, aardvarks, mongooses
• Tertiary Consumers: Wild dogs, lions, cheetahs, caracals, servals,
eagles.

12. • The savanna food web might
start with a warthog eating
star grass. The warthog can
then be caught and eaten by
the lion or wild dog.
• Another example would be of
a termite eating the red oat
grass. That termite might then
be eaten by the mongoose or
the serval. But the mongoose
can be eaten by the caracal,
too.

13. Marine
• Underwater creatures
• Producers and Decomposers: Seagrass, seaweed, algae, plankton,
bacteria
• Primary Consumers: Turtles, damselfish, crab, shrimp
• Secondary Consumers: Octopuses, triggerfish, squid, krill
• Tertiary Consumers: Seagulls, penguins, elephant seals, whales

14. If you were to watch the
food web happen
underwater, you would
see krill eat plankton.
The krill would then be
eaten by fish or a whale.
That fish might be eaten
by a seagull or a seal.

15. • Food chains, food web, are the part of the ecosystem that
can be described as the community of the smallest
microorganisms, plants to the higher animals that feed, live,
reproduce, interact and die in the same area or environment.
All ecosystems have feeding hierarchy which includes the sun
(energy source), producer, consumer, and decomposer.

16. • But in an ecosystem, it is impossible to have a single food chain. To
survive, the organisms feed on the different trophic levels. So in the
food web, different food chains are linked together as well as
crisscross each other to form a complex network. The food web
enhances the competitiveness and adaptability among organisms, but
it is not seen in the food chain

17. TROPHIC LEVEL
• Each level in a food web is a trophic level. This means that energy is
transferred from one organism to another, or from one trophic level
to another. At the beginning of the food web are the producers or
autotrophs. The producers are then eaten by the consumers or
heterotrophs, which include primary, secondary, and tertiary
consumers, plus the decomposers

18. FOOD PYRAMID/ENERGY PYRAMID
• A food pyramid takes the
food chain but uses it to
show how energy moves
through a community.

19. • Because each organism uses some of the energy it received from the
previous level for growth and other processes, the energy available to
the next level is less (because some of that energy has been used).
This is why we have more primary producers than carnivores.