Download Lesson 1 - Ecology

Grade 10 Science – Unit 1 Lesson 1
Ideas about Ecology
What is Ecology?
Ecology is the study of how organisms interact
with each other and their physical environment.
Ecology is interrelationships…between different
organisms AND between organisms and their
environment (often non-living (e.g., sunlight, water).
Among other things, ecology includes (1) Predator-Prey
Relationships, (3) competition for resources and (3) the
transfer of energy among organisms.
Organisms can be grouped into two general ecological
classes: (1) Producers and Consumers.
In simple terms, a Producer is an organism that can
make its own energy. For example, plants use
sunlight and chemicals to make sugar (i.e., energy)
for growth
Consumers are organisms that cannot make their
own energy. Consumers must eat other organisms to
get energy. There are four groups of Consumers.
Herbivore - An organism that eats only plants.
Carnivore – An organism that eats meat.
Omnivore – An organism that eats both plants
and meat.
Decomposer - An organism that feeds or obtains
nutrients by breaking down organic matter from
dead organisms. Examples are bacteria and
fungi.
It is important to understand that organisms, to survive and thrive, minimize
competition with other organisms. It may appear that lions and cheetah may eat
the same prey (e.g., zebra, wildebeest, antelope). In reality, the lion hunts in
packs and typically preys on the slower or weaker animal (e.g., young, old, sick),
while the cheetah uses speed to often bring down the stronger animals. The
different hunting style reduces resource competition, and it allows both
organisms to effectively live.
The structure of feeding and energy flow -- Predator-Prey Relationships -- is
described by two terms: (1) Food Chains and (2) Food Webs.
Food Chain - A series of organisms connected by
their feeding habits with each link in the food chain
eaten by the next larger link. This feeding
relationship allows for the flows of nutrients (i.e.,
energy) up the chain.
Food Web – A network of many Food
Chains. NOTE: A Food Web is not a
straight line…like a Food Chain. A Food
Web is many interconnections in which an
organism can eat many other organisms
and, at the same time, it can be the prey of
many organisms. As illustrated in the
picture, a fox and cougar both eat rabbits,
but the cougar may also eat the fox.
Practice
Construct a Food Web using the following list of organisms
Grass
Human
Deer
Wild Strawberries
Wolf
Bacteria (Microscopic)
Algae (Microscopic water plant)
Brown Bear
Human
Frog
Tadpole
Perch (Fish)
Cow
Rabbit
Hawk
Corn
Grasshopper
Mouse