Grade 4: Science_LivingThings_Ch5 Flashcards
Life Science: Chapter 3 Study Guide "Living Things Interact" December 24, 2012
Individual
single organism in an environment.
Population
individuals of the same species living in the same environment.
example: human population, lion population, whale population
Community
populations of different organisms living together in an environment.
example: residents of the neighborhood
Ecosystem
Ecosystem is made up of communities of organisms together with the physical environment.
example: prairie ecosystem, mountain ecosystem, desert ecosystem, sea ecosystem.
Habitat
a place where every population lives in
example: neighborhoods.
Niche
a role of the population.
example: eagles hunt mice during the day while owls hunt mice during the night
Producers
organism that uses sunlight to make their own food energy.
example: plants depend on sunlight to make food energy
Consumers
organism that eats other organisms in order to get food energy.
animals in the community that depends on eating to get food energy.
Decomposers
consumers that break down and recycle the tissues of dead organisms.
they use the some nutrients from the dead tissues as food.
examples: mushrooms, bacterias
Food chain
the order where the consumers in an ecosystem are connected to one another according to what they eat
Food web
the feeding relationships between many different food chains in a single ecosystem.
Food web shows how organisms may be part of several food chains at the same time.
example:
prairie food chain…
prairie grass is eaten by bison
prairie grass is eaten by mice… eaten by snakes… eaten by hawks
Energy pyramid
shows the amount of food energy available to pass from one level of a food chain to the next.
Symbiosis
a long-term relationship between different kinds of organisms.
Competition
a contest among organisms to get the limited supplies of food resources.
example:
plants compete for water and sunlight
animals compete for water and shelter
Extinct
where the last individual in the population dies and the organism is gone forever
Threatened
organisms that are likely to become endangered if they are not protected by law.
example: bald eagle, California sea otter
Endangered
organisms where its population is so small that they are likely to become extinct.
Example:
American crocodile, California condor
What makes up a healthy ecosystem
a healthy ecosystem is where the populations depends on each other for survival.
for example,
mice may eat one type of plant.
owls hunt mice at night and eagles hunt mice during the day.
the two birds prevent the mice from over-populating and the plant population never dies out.
if there are too many owls and not enough mice, some of the owls will die.
Limiting factors in a ecosystem
The limiting factors in a ecosystem, such as the amount of food, affect population density.
For example, one area may have enough food to support 100 deers. Another area of the same size but fewer plants may only support 50 deers.
What is the role of a producer, consumer and decomposer take in a food chain
Producers are plants that use sunlight and nutrients from the soil to make food energy they need.
There are several levels of consumers.
First-level consumers, called herbivores, eat the producers.
Second-level consumers, called carnivores, eat the first-level consumers.
Third-level consumers eat the second-level consumers, and so on.
Decomposers help connect both end of the food chain.
Decomposers, like mushrooms and bacteria, are consumers that break down dead organisms and use the dead tissue as food. The remains of the dead organisms become part of the soil. The soil that have a lot of nutrients helps plant grow.
How do energy pass through an energy pyramid
organisms uses about 90 percent of the eaten organisms stored food energy to stay alive and stores the other 10 percent in its body tissue.
only 10 percent of the energy is passed on to organisms in the next higher level of the energy pyramid.
higher level consumers, such as wolves or hawks, have small populations because there’s not enough energy to support a large population of wolves or hawks
producer population is the largest because it provides energy for all consumer levels in the Energy Pyramid.
How do organisms compete and share resources
Animals have adapted to help compete for food. Example, cheetah’s speed help hunt and capture fast preys like zebras and antelopes. Hyenas hunt in large packs where they can chase a cheetah away from its captured prey.
Other animals have adapted to share the same food resources. For example, giraffes’ neck and long legs can help reach the high branches to eat, antelopes don’t have very long necks and not very tall like the giraffes but they can stand on their hind legs and can eat from the middle branches and rhinos have short necks and are heavy, so they can eat from the lower branches.
Mutualism versus Parasitism
Mutualism is a relationship where both organisms benefit and help each other grow.
example: flowers produces nectar that bees eat. while bees eat the flower, they pollinate the flowers.
Parasitism is where only one organism (the parasite) gains energy at the expense of the other (the host).
Parasites usually harm the host.
example: mosquitoes and ticks feed on warm-blooded animals, like birds, deers, and people.
Why do some organisms become extinct
Natural disasters that change the environment, like fires, erupting volcano or drought, resulted in extinction of organisms because it may kill producers in a food chain and cause consumer population to decline and become extinct. Example dinosaurs.
Also, human activity that create habitat destruction will cause extinction at a faster rate.
For example, people cutting down many trees from a forest habitat will cause the extinction of some rare animals that depends on living in that forest habitat
