O What is a population? Chapter 21, Lesson 1: POPULATIONS o

[Pages:2]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

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