POPULATIONS AND
COMMUNITIES
Chapter 14
LIVING THINGS AND THE
ENVIRONMENT
LESSON 1
ORGANISM
An organism gets food, water, shelter and other
things it needs to live, grow and reproduce from
its environment.
 Lemurs
 Are
 Primates

PRIMATES
According to fossil evidence, the primitive
ancestors of primates may have existed in the
late CRETACEOUS period, around 65 million
years ago.
 Characteristics:
 Generally Mammals
 Primarily Terrestrial than arboreal.
 Locomotion techniques: leaping.
 Three color vision.
 Opposable thumbs.
 Prehensile tails.
 Large Brains.

PRIMATES
Primates arose from ancestors that lived in the
trees of tropical forests.
 Guinea Baboons

BABOONS
Kingdom:Animalia
 Phylum:Chordata
 Class:Mammalia
 Infraclass:Eutheria
 Superorder:Euarchontoglires
 Order:Primates

HABITAT
It is the environment that provides the resources
a specific organism needs to live, grow and
reproduce.
 Prairie Dog

NICHE
Niche is how an organism makes a living.
 The ecological niche describes how an organism
or population responds to the distribution of
resources and competitors (e.g., by growing when
resources are abundant, and when predators,
parasites and pathogens are scarce)

HABITAT
INTERACTION WITH THE ENVIRONMENT

An organism interacts with living ( biotic ) factors
and nonliving ( abiotic ) parts of its habitat.
HABITAT . ABIOTIC FACTORS

1. oxygen
2. carbon dioxide
3. sunlight
4. wind
5.water
6. soil
7. temperature
HABITAT. BIOTIC FACTORS
Plants
 Seeds
 Berries
 Grass
 Animals
White
Tail
Deer
 Humans

ORGANIZATION OF AN
ECOSYSTEM
Cell
 Tissue
 Organ
 Organ System
 Organism
 Species
 Populations
 Communities
 Ecosystems
 Biome
 Biosphere

ECOLOGICAL LEVELS
ECOLOGY


Because the populations in an ecosystem interact
with one another, any change affects all the
different populations that live there.
The study of how organisms interact with each
other and with their environment is called …
ECOLOGY.
ECOLOGY
ENERGY FLOW IN ECOSYSTEMS

Each of the organisms in an ecosystem fills the
energy role of producer, consumer or decomposer.
ENERGY FLOW IN THE
ECOSYSTEM
LESSON 2
THROPIC LEVELS
Levels of feeding in a food web of organisms.
 Producers
Autotrophic
 Primary Consumer
 Secondary Consumer
 Tertiary Consumer
Heterotrophic
 Quaternary Consumer
 Decomposer

PRODUCERS
Producers are the source of all the food in an
ecosystem.
 Producers obtain energy from sunlight and store
it as food energy. These organisms use the sun’s
energy to turn water and carbon dioxide into food
molecules in a process called photosynthesis.
 Certain bacteria produce their own food using the
energy in hydrogen sulfide, a gas that is
present in their environment.

PRODUCERS
CONSUMERS

An organism that obtains energy by feeding on
other organisms is a consumer.
Herbivores.- Eat plants.
 Carnivores.- Eat animals.
 Omnivores.- Both plants and animals.
 Scavenger.- Carnivore that feeds on bodies of
dead organisms.

THROPIC LEVELS

We can also categorize animals on the basis of
the exact type of food they eat.
Detritivore.- Eats dead organic matter (
detritus)
but does not decompose it.
 Insectivore.- Eats insects.
 Frugivore.- Eats fruits.

CONSUMERS HERVIBORES
CONSUMERS CARNIVORES
CONSUMERS OMNIVORES
CONSUMERS SCAVENGERS
CONSUMERS
DECOMPOSERS
Decomposers break down wastes and dead
organisms and return raw materials to the
environment.
 Carbon and Nitrogen ( raw materials )
 Example:
 Bacteria
 Fungi
 Mushrooms

DECOMPOSER
FOOD CHAIN


A food chain is a series of events in which one
organism eats another and obtains energy.
Energy moves through an ecosystem when one
organism eats another.
ENERGY
Energy can exist in different forms:
 Heat
 Light
 Potential Energy
 Kinetic Energy
 Electrical Energy
 Chemical Energy

FOOD CHAIN
FOOD WEB


A food web consists of many overlapping food
chains in an ecosystem.
Organisms play more than one role in an
ecosystem.
FOOD WEB
FOOD WEB
ENERGY PYRAMID

The most energy is available at the producer
level of the pyramid. As energy moves up the
pyramid, each level has less energy available
than the level below.
ENERGY PYRAMID
CARRYING CAPACITY


Because amounts of matter and energy in an
ecosystem are limited ,population growth within
the ecosystem is limited too.
The largest population that an environment can
support at any given time is called carrying
capacity.
INTERACTIONS AMONG
LIVING THINGS
LESSON 3
NATURAL SELECTION


A characteristic that makes an individual better
suited to a specific environment may eventually
become common in that species through a process
called natural selection.
Individuals whose unique characteristics are
well- suited for an environment tend to survive
and produce more offspring.
NATURAL SELECTION
ADAPTATION

The behaviors and physical characteristics that
allow organisms to live successfully in their
environment is an adaptation.
ADAPTATION
NICHE

The role of an organism in its habitat is called
niche.
COMPETITION

The struggle between organisms to survive as
they attempt to use the same limited resources is
called competition.
Alder Flycatcher
Barn Owl
PREDATION

An interaction in which one organism kills
another for food or nutrients is called predation.
The organism that does the killing is the
predator.
 The organism that is killed is the prey.

SYMBIOSIS

Symbiosis is any relationship in which two
species live closely together and at least one of
the species benefits.
The three types of symbiotic relationships are:
 Mutualism
 Commensalism
 Parasitism

MUTUALISM
In some relationships, two species may depend on
one another.
 A relationship in which both species benefit is
called mutualism.

Anemone and Black
Finned Clown Fish
MUTUALISM
Red Billed Oxpecker
and African Buffalo
MUTUALISM
Whale shark and remora
MUTUALISM

Gray Whales and Barnacles. ( Transportation to
nutrient- rich ocean waters )
COMENSALISM
Commensalism is the relationship in which one
species benefits and the other species is neither
help nor harmed.
 In native commensalism is not very common
because two species are usually either helped or
harmed a little by an interaction.

COMENSALISM

Ladybugs live on plants, eating the aphids and
benefiting by getting food, while the plant
benefits by being rid of the aphids.
COMENSALISM


An example would be mosses living on the bark
of a tree.
PARASITISM

A relationship that involves an organism living
with, on, or inside another organism and
harming it is called parasitism.
The organism that benefits is called parasite.
 The organism it lives on or in is called a host.

PARASITISM
Lemon Shark and Shark suckers
PARASITISM

TICK in Human Skin
TICK. Ixodes Ricinus
PARASITISM

House Dust Mite
BIRTH RATE
The birth rate of a population is the number of
births in a specific population in a certain time
period.
 Example 1,750 cottontail rabbits are born per
year.

DEATH RATE
Death rate is the number of deaths in a specific
population in a certain time period.
 Example:
 1,200 rabbits die in a year.

IMMIGRATION
It means moving into a population.
 Geese in New Mexico.

EMIGRATION

It means leaving a population.
POPULATION DENSITY


It is the number of individuals in an area of a
specific size.
Population density = Number of Individuals
Unit of AREA
LIMITING FACTOR
A limiting factor is an environmental factor that
causes a population to stop growing or decrease.
 Some limiting factors are:
1. Food
2. Shelter
3. Water
4. Space
5. Disease
6. Parasitism
7. Predation
8. Nesting

CARRYING CAPACITY

The largest population that an area can support
its called carrying capacity.