1.
Ecological
Relationships
UNIT FIVE, LESSON 5.3
BY MARGIELENE D. JUDAN

2.
LESSON OUTLINE
Ecological Relationships
Symbiosis

3.
Different species of organisms
within the community interact
with each other as a part of
their ecological niche.
Types of interaction:
Organism of same species
Organism of different species

4.
ECOLOGICAL RELATIONSHIPS
Pertain to the
interaction
between or
among two
different
species of
organisms.

5.
ECOLOGICAL RELATIONSHIPS
Includes the following:
1. Symbiosis
2. Predation
3. Competition
4. Cooperation

6.
SYMBIOSIS
Type of relationship
between two diff. organisms
where one benefits and the
other is unaffected or
affected, or both of them
benefit.

7.
SYMBIOSIS
Kinds of Symbiotic
Interactions:
1. Mutualism
2. Commensalism
3. Parasitism

8.
1. Mutualism
Referred to as the “perfect
relationship”
Two organisms both benefit
from each other

9.
1. Mutualism
Examples:
The bee and the flower
Bees fly from flower to flower gathering
nectar, which they make into food,
benefiting the bees. When they land in a
flower, the bees get some pollen on their
hairy bodies, and when they land in the
next flower, some of the pollen from the
first one rubs off, pollinating the plant.
This benefits the plants. In this mutualistic
relationship, the bees get to eat, and the
flowering plants get to reproduce.

10.
1. Mutualism
Examples:
The bacteria and the human
A certain kind of bacteria lives in the
intestines of humans and many other
animals. The human cannot digest all of the
food that it eats. The bacteria eat the food
that the human cannot digest and partially
digest it, allowing the human to finish the
job. The bacteria benefit by getting food,
and the human benefits by being able to
digest the food it eats.

11.
1. Mutualism
In some cases, two different species
of became one, which if separate,
both of them will die. This happens in
lichens. Lichens are produced
because of the mutualistic relation
bet. An alga and a fungus. Thus
fungus protects the alga from harsh
temperature change while the alga
nurtures the fungus.

12.
2. Commensalism
One organism benefits
while the other is not
affected

13.
2. Commensalism
Example:
Anemone and clownfish
Clownfish lives in the tentacles of the
anemones which protects them from
predators. Predators are poisoned by the
nematocysts of the anemones. The
clownfish benefits but the anemone is
neither affected.

14.
3. Parasitism
One organism benefits
while the other is affected
Parasites – organisms that
benefit
Host – organisms affected

15.
3. Parasitism
There are two types of parasites:
1. Endoparasites (inside) – ex. worms in he intestine
2. Ectoparasites (outside) – ex. mosquitoes sucking
blood from your skin
Another example: Students become parasites by
always asking for a sheet of paper to those who have.

16.
PREDATION
One species of organisms
harm or eat the other species
of organisms.
Especially common among
carnivores.
Predator – organisms that
harm or eat
Prey – organisms being
harmed or eaten

17.
COMPETITION
Organisms tend to compete
for food, shelter, and the like.
Types of competition:
1. Intraspecific – bet. 2 same
species
2. Interspecific – bet. 2
different species

18.
COMPETITION
Examples:
Intraspecific – two deer
competes for space
Interspecific – different
species of plants compete for
sunlight; a cat and a dog
compete for food

19.
COOPERATION
Organisms cooperate with
each other
Ex. (working ants, humans,
herds of cattle arrange
themselves so that the
strongest are on the outside)

20.
Animals are social
beings too.
Another benefit
that social living
brings is the
division of labor. It
is quite common
among insects.

21.
For instance, in a colony of honeybees, only the queen is
allowed in a hive at any time. Her only function for her
lifetime is to produce eggs. The male bees, called drones,
serve merely as the queen’s mates and eventually are
driven out of the hive or killed. The sterile female workers
perform all the tasks needed to maintain the colony and
attend to the needs of the queen. Some workers look for
food; other build and clean the hive and guard it from
intruders. Notice the division in labor.

22.
Output: Write Up (1/2 sheet of paper)
Which of the following ecological relationships do
you like best and why? Give practical examples.
Minimum of 5 sentences. (10 pts)

23.
Assignment: Bond paper (short) Lab 2.3
Answer “Check Your Understanding”, p. 183, #2

24.
Sources:
Science Links 7
http://www.necsi.edu/projects/evolution/co-
evolution/mutualistic/co-evolution_mutualistic.html
http://examples.yourdictionary.com/commensalism-
examples.html