Grade 4: Science_LivingThings_Ch5

Question 1

Individual

Answer 1

single organism in an environment.

Question 2

Population

Answer 2

individuals of the same species living in the same environment.

example: human population, lion population, whale population

Question 3

Community

Answer 3

populations of different organisms living together in an environment.

example: residents of the neighborhood

Question 4

Ecosystem

Answer 4

Ecosystem is made up of communities of organisms together with the physical environment.

example: prairie ecosystem, mountain ecosystem, desert ecosystem, sea ecosystem.

Question 5

Habitat

Answer 5

a place where every population lives in

example: neighborhoods.

Question 6

Niche

Answer 6

a role of the population.

example: eagles hunt mice during the day while owls hunt mice during the night

Question 7

Producers

Answer 7

organism that uses sunlight to make their own food energy.

example: plants depend on sunlight to make food energy

Question 8

Consumers

Answer 8

organism that eats other organisms in order to get food energy.

animals in the community that depends on eating to get food energy.

Question 9

Decomposers

Answer 9

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

Question 10

Food chain

Answer 10

the order where the consumers in an ecosystem are connected to one another according to what they eat

Question 11

Food web

Answer 11

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

Question 12

Energy pyramid

Answer 12

shows the amount of food energy available to pass from one level of a food chain to the next.

Question 13

Symbiosis

Answer 13

a long-term relationship between different kinds of organisms.

Question 14

Competition

Answer 14

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

Question 15

Extinct

Answer 15

where the last individual in the population dies and the organism is gone forever

Question 16

Threatened

Answer 16

organisms that are likely to become endangered if they are not protected by law.

example: bald eagle, California sea otter

Question 17

Endangered

Answer 17

organisms where its population is so small that they are likely to become extinct.

Example:
American crocodile, California condor

Question 18

What makes up a healthy ecosystem

Answer 18

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.

Question 19

Limiting factors in a ecosystem

Answer 19

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.

Question 20

What is the role of a producer, consumer and decomposer take in a food chain

Answer 20

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.

Question 21

How do energy pass through an energy pyramid

Answer 21

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.

Question 22

How do organisms compete and share resources

Answer 22

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.

Question 23

Mutualism versus Parasitism

Answer 23

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.

Question 24

Why do some organisms become extinct

Answer 24

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