The main Organs
An environmental factor that stops population growth or causes it to decrease.
Limiting factor
A community and the nonliving environment
An ecosystem
The study of how organisms interact with each other and with their environment.
Ecology
Define food chain.
A series of events where one organism eats another
Immigration decreases population size.T/F
False
Organisms that can mate and produce fertile offspring
A species
All members of one species in an area
A population
The carrying capacity of an area is:
The largest population it can support
Explain the importance of decomposers in an ecosystem.
they break down dead plants and animals, returning nutrients to the soil for use by producers. Without decomposers, waste and dead material would build up and nutrients would not be recycled.
The environment that provides an organism’s needs
Habitat
A place where an organism lives and gets resources
Habitat
An organism that eats both plants and animals
omnivore
Which of the following is a decomposer?
Rabbit or Mushroom
Mushroom
Describe how energy moves through an ecosystem using a food chain example.
Energy moves through an ecosystem in a food chain by starting with the sun, which gives energy to plants (producers). Then, a grasshopper eats the plant, a frog eats the grasshopper, and a snake eats the frog. At each step, energy is transferred from one organism to another.
The process by which plants use sunlight to make food
photosynthesis
What is the main source of energy for most ecosystems?
Sunlight
What happens to energy as it moves up an energy pyramid?
It decreases
Give two abiotic and two biotic factors from a pond habitat.
Abiotic: water, temperature, rock, sand. Biotic: fish, algae, plants, humans, animals
Which process is responsible for recycling nutrients back into the soil?
Decomposition
Define a food web.
Overlapping food chains in an ecosystem
How can climate and weather affect populations?
Changes (like warmer early winters or floods) can increase growth temporarily or reduce populations through immediate and long-term effects.
How do birth and death rates affect population size?
If birth rate > death rate, the population grows; if equal, it stays stable; if death rate > birth rate, it decreases.
What is the difference between immigration and emigration?
Immigration = moving into a population; emigration = leaving a population.
What makes up a community in an ecosystem?
All the different populations that live together in an area.
Calculate the population density if 1,000 beetles live in an area of 5 square miles.
Population density = 1,000 ÷ 5 = 200 beetles per square mile.