Clint Ryan U. Lestino I-Alpha
GEC 21 People and Earth’s Ecosystem
Activity 6
Food Web and Food Chain
3rd Trophic Level
Secondary Consumer
2nd Trophic Level
Primary Consumer
1st Trophic Level
Producer
3rd Trophic Level
2nd Trophic Level
Secondary Consumer
Primary Consumer
1st Trophic Level
Source of Energy
Producer
1st Trophic Level
Producer
1st Trophic Level
Producer
2nd Trophic Level
Primary Consumer
3rd Trophic Level
Secondary Consumer
2nd Trophic Level
3rd Trophic Level
Primary Consumer
Secondary Consumer
Analysis Questions:
1. What is the ultimate source of energy for the most organisms and how is this energy captured
so it is useful in a food chain?

The ultimate source of energy for the most living organisms including people is
none other than the sun. The sun provides solar energy which can be
converted to various types of energy, which is also greatly essential for plants
to photosynthesize in order to produce food for people and animals.
2. What always starts off a food chain? What ends it?

The start of a food chain is the producer and what ends it is the detritivores or
decomposers.
3. What is the role of carnivores? Herbivores?

The carnivores are important in an ecosystem because they prevent the prey
population becoming too large. Herbivores also function just like the
carnivores; they prevent overgrowth of vegetation thus both maintains the
healthiness of the ecosystem.
4. Why are there no more than four or five links in a food chain?
 This is because the animals at the higher trophic level or situated at the near end of
the chain would not get enough food if ever there are more than 4-5 links on the first
levels of the chain.
5. Why is a food web a better description of feeding relationships in a community than a food
chain??

The food web presents more clarity in the interactions between the animals
whereas the food chain is simply a linear representation of the consumption of
the animals involved.
6. Imagine a massive population crash occurs in the rabbits in this food web. List two populations
which could be influenced by this in the food web and completely explain why the crash in the
rabbit population would have this effect.

The coyotes would be the primary population would be greatly affected by the
crash because their food supply would be diminished thus increasing the
competitions which can result to the decline of the population. The grasses and
shrubs will increase also because its consumer count was diminished by one.
7. Select one other species besides rabbits in this food web and explain how the removal of this
species would influence another species population in this food web.

If the grasses and shrubs are going to suddenly go in decline it will cripple the
food web. Primarily the insects, rats, birds, and rabbits will be affected and if
these populations will decrease so will the population of next order consumers
like the hawk, snake, coyotes, etc.