4th Grade Life Sciences
Study Guide for final test

ecosystem   =
 all the living and non-living things that interact in an area examples:  Living:  plants, animals, insects  Non-living: air, water, sunlight
organisms  =
 a living thing.  All organisms have basic needs.
energy  = the ability to cause change.  The source of all energy is the sun.
oxygen  =
 one of the gases in the air.  Plants give off oxygen.  Humans need oxygen to breathe.
environment  =
 		everything that surrounds and affects organisms
community  =
 		all the organisms in an ecosystem
population  =
 		all the members of one kind of plant or animal in a community
interdependence  =
 		all living things need each other to meet their needs.
producer  =
 		an organism that makes its own food
consumer  =
 		an organism that gets its energy by eating plants, or other animals that eat plants
pollinator  =
 		an animal that helps plants make seeds by moving pollen.example:  bees, butterflies
seed dispersal  =
 		animals carry seeds to new plants where they can grow examples:  birds drop seeds and fruit, squirrels bury acorns
habitat  =
 		the place where a plant or animal lives is its habitat
adaptation  =
 		a physical feature or a behavior that helps a plant or animal survive
predator  =
 		animals that hunt other animals for food
prey  =
 		any animal that is hunted for food by a predator
camouflage  =
 		the coloring, makings, or other physical appearance of an animal that helps it blend in with its surroundings
food chain  =
 		the path of food energy from sun to plants to animals
food web  =
 		when two or more food chains overlap
scavenger  =
 		an animal that feeds on the remains of dead animals
decomposer  =
 		a living thing that breaks down the remains of dead organisms
pollution  =
 		harmful materials added to our environment
litter  =
 		trash that is thrown carelessly on the ground or in water
hazardous waste  =
 		a substance that can pollute the environment even in small amounts because it is so harmful
biodegradable material =
 		matter that breaks down easily in the environment


Know that the trash we throw away goes to landfills that cannot break down in the environment.  Why? Because the landfill is packed so tightly that microorganisms that break down materials cannot survive there.  So the garbage does not decay.  Also, landfills take up a lot of space, and people don't want to live near them so it's hard to find room for more.  The best solution is recycling, reusing, and composting.

recycling  =
 		separate trash into paper, plastic, and aluminum.  Send these separate items to a recycling center where these materials are turned into new products.
reusing   =
 		don't throw materials away that can be cleaned and reused.
composting=  
placing items like leaves, kitchen scraps, and some papers into a special bin where, heated by the sun, and mixed regularly, decomposers such as fungi and bacteria will break down the materials so they can be mixed back into the soil and enrich it.