FOOD CHAIN AND FOOD WEB

What is food chain?

Transfer of energy from one trophic level to another  trophic level is called food chain.
Trophic Levels:
The trophic level of an organism is the position it holds in a food chain.

1. Primary producers (organisms that make their own food from sunlight and/or chemical energy from deep sea vents) are the base of every food chain - these organisms are called autotrophs.
2. Primary consumers are animals that eat primary producers; they are also called herbivores (plant-eaters).
3. Secondary consumers eat primary consumers. They are carnivores (meat-eaters) and omnivores (animals that eat both animals and plants).
4. Tertiary consumers eat secondary consumers.
5. Quaternary consumers eat tertiary consumers.
6. Food chains "end" with top predators, animals that have little or no natural enemies.

 For getting better understanding please see this video

Food Web

A network of many food chains is called a food web.

What is the difference between food Chain and a food web?

Food chains follow a single path as animals eat each other.

EXAMPLE:            

The sun provides food for grass

The grass is eaten by a grasshopper

The grasshopper is eaten by a frog

The frog is eaten by a snake

The snake is eaten by a hawk.

Food webs show how plants & animals are interconnected by different paths.

EXAMPLE:

Trees produce acorns which act as food for many mice and insects.

Because there are many mice, weasels and snakes have food.

The insects and the acorns also attract birds, skunks, and opossums.

With the skunks, opposums, weasels and mice around, hawks,

foxes, and owls can find food.

They are all connected! Like a spiders web, if one part is removed, itcan affect the whole web.

Food webs show how plants and animals are connected in many ways toHelp them all survive. 

Food chains follow just one path of energy as

Animals find food.

Learning Activity:  FOOD CHAINS & FOOD WEBS

FOOD CHAINS AND FOOD WEBS – Worksheet

¨       Food Chain:

A food chain is the series of organisms showing feeding relationships.

A food chain almost always begins with a green                   (producer) which is eaten by an                          (consumer).

The arrow means ‘is eaten by’, and shows the flow of matter and energy along the food chain.

There are no                                                 in a food chain because they are so widespread and are not specific to just one food chain.

¨       Example of a Food Chain

Grass(Producer)        Grasshopper(1^st order Consumer)      Kookaburra(2^nd order Consumer)

¨       Producer – usually a green plant that produces its own food by                   

¨       First-order Consumer (also called the primary consumer) – the organism that eats the                                           

¨       Second-order Consumer (also called the secondary consumer) – the organism that eats or derives nutrients from the                                                                  

¨       Herbivore –                                                                                                           

¨       Carnivore – an organism that obtains nutrients from an                                  blood or flesh

¨       Omnivore – an organism which eats both                                                    

¨       Scavenger – an consumer that eats                          animals (e.g. crab)

¨       Detritivore – a consumer that obtains its nutrients from detritus

¨       Decomposer - an organism such as                                      or fungi that breaks down dead organisms and their wastes

¨       Trophic Level – A trophic level is each level in a food                                  . Matter and energy are always ‘lost’ as urine, faeces and heat energy at each trophic level.

¨       Food Web – a                                 of interrelated food chains in a given area

Description of Biotic Component

Sub-division under biotic component 

1. Producers [Autotrophic]
2. consumers [Hetrotrophic] 
3. Decomposers   

Producers - Producers are autotrophic because they prepare their food by its own by the 
process of photosynthesis e. g. Plants. Producers are any kind of green plant. Green plants make their food by taking sunlight and using the energy to make sugar.

Consumers - Consumers are heterotrophic because it depends on other. Consumers have to feed on producers or other consumers to survive. Deer are herbivores, which means that they only eat plants (Producers). Bears are another example of consumers.

Decomposers - Decompose dead and decay material ,e.G. In form of bacterias,fungi. Decomposers are the garbage men of the animal kingdom; they take all the dead animals and plants (consumers and decomposers) and break them down into their nutrient components so that plants can use them to make more food.

Revise your learning 

Multiple choice questions

Q1. An example of a producer is a

  a.  fungus

  b.  caterpillar

  c.  bird

  d.  moss

Q2. An example of a consumer in a pond ecosystem is:

  a.  a water lily

  b.  algae

  c.  a reed

  d.  a frog  

Q3. Both consumers and producers are a source of food for:

  a.  scavengers

  b.  decomposers

  c.  carnivores

  d.  herbivores

Q4. A caterpillar eats a leaf, and a bird eats the caterpillar.  In this interaction, the bird is a: 

  a. producer

  b. herbivore

  c. primary consumer

  d. secondary consumer 

Q5. An animal that eats only plants is a:

  

  a. primary consumer

  b.  secondary consumer

  c.  tertiary consumer

  d.  primary producer

 

 

What is ecology ?

The study of living organisms and how they interact with their physical environment.

What is ecosystem ?

A functional unit of environment that includes all living organisms and physical features within a given area.

Component of ecosystem

What are biotic component ?

  Biotic components: it consists of all living organisms ,i.e. Cats,dog,tiger,any human body ,etc.

 What are abiotic component ?

Abiotic components:it consists of all non-living organisms ,i.E. Wooden material,electronic materials,buildings,ice bergs ,etc.

For getting better understanding please see this video

 Revise your learning

Multiple choice questions

Ecology is the study of how:

  a.  the physical environment changes   over time

  b.  biotic factors change over time

  c.  matter interacts with energy in our   environment

  d.  living things interact with each other   and their environment

 

An ecosystem is made up of:

  a.  living things only

  b.  physical environment only

  c.  living things and the physical   environment

  d.  living things and decaying matter

A scientist who studies the interactions of plants and animals is called:

  a. a physicist

  b. a botanist

  c. a geologist

  d. an ecologist

Which of the following factors in an ecosystem is biotic?

  a.  insects

  b.  soil

  c.  water

  d.  sunlight

 

Biotic factors in an ecosystem may include:

  a.  bacteria, soil, and water

  b.  plants, animals, and bacteria

  c.  temperature, water, and soil

  d.  animals, fungi, and temperature

 

An example of a biotic factor is:

  a.  soil

  b.  a rock

  c.  water

  d.  a tree

Fill in the blanks

__________________________ is the study of how living things interact with each other and their environment.

Living things in an ecosystem are ________________________ factors.

 

Nonliving things in an ecosystem are __________________________ factors.

True or Falls .

Organisms in soil are an example of abiotic factors.               (      )

An ecosystem is composed of biotic factors.                           (      )

Plants use energy to make sugars through photosynthesis.    (     )