o What is a population?

o What affects the size of a

population?

VOCAB:

Biosphere

Biotic potential

Carrying capacity

Community

Competition

Limiting Factor

Population

Population Density

Chapter 21, Lesson 1: POPULATIONS biosphere parts of Earth and the atmosphere where there

is life (all land & water)

population all the organisms of the same species that live

in the same area at the same time

community all the populations of different species living in

the same area at the same time

competition struggle in a community for the same

resources.

o Who competes? Individuals within a population;

and all the populations in a community

limiting factor anything that restricts the size of a

population

o Resource availability – food, water, shelter;

climate; sunlight; disease; predation; disaster

biotic potential potential growth of a population in perfect

with no limiting factors

population density size of a population compared to the

amount of space available

carrying capacity largest number of individuals of one

species that an environment can support

o What events can change a

population?

VOCAB:

Birth rate

Death rate

Endangered species

Extinct species

Migration

Threatened species

o How do the populations in

a community interact?

VOCAB:

Commensalism

Habitat

Mutualism

Niche

Parasitism

Predator

Symbiosis

Chapter 21, Lesson 2: CHANGING POPULATIONS 3 major factors that affect population size:

o birthrate number of offspring produced (born)

over a given time period

o death rate number of individuals that die over

a given time period

o migration instinctive seasonal movement of a

population

When a population is in ideal conditions with unlimited

resources, it grows in a pattern called exponential growth. o as a population gets larger, it grows at a faster rate

extinct species = none left

endangered species = at risk of extinction

threatened species = at risk but not yet endangered

Chapter 21, Lesson 3: COMMUNITIES habitat place within an ecosystem where an organism

lives

niche what a species does in its habitat to survive

producer organism that gets energy from making its

own food

consumer organism that gets energy by eating other

organisms

predator organism that survives by hunting

symbiosis close, long-term relationship between two

species that usually involves exchange of food and

energy

o commensalism symbiotic relationship that

benefits one species but does not harm or

benefit the other

o mutualism symbiotic relationship in which

both partners benefit

o parasitism symbiotic relationship that benefits

one species and harms the other