Effects of Ecosystem Change / Study Guide

Effects of Ecosystem Change / Study Guide

How Organisms Adapt

Ecosystems are made up of living and nonliving things that interact. A change to one part of the ecoystem affects the whole system. This diagram depicts a basic food chain where the mouse eats the grass and the fox eats the mouse. The next few slides will show how this food chain would be affected by changes in an ecosystem

On the East Coast of the United States, humans have caused an overpopulation of deer by destroying their habitats and limiting the areas where people can hunt them. This has caused the deer population to grow out of control. This has resulted in many problems in the deer's habitats.

Multiple Choice

Deer can be _______ to humans when cars hit the deer.

• hepful

• dangerous

Multiple Choice

There are areas of forest where the deer have eaten too many leaves off of the trees and they have stripped them of their bark. This _______ the trees.

• increases the growth of

• kills

Multiple Choice

Animals that depend on the trees that the deer destroyed have had a ________ in population.

• decrease

• increase

Multiple Choice

The number of coyotes and wolves has _________ because they have more deer to hunt and eat.

• increased

• decreased

Multiple Select

People in Africa have started to kill rhinos for their horns. What could happen if there is a decrease in the rhino population?

• The population of plants that rhinos eat will decrease.

• Animals that eat rhinos will start to die.

• There will be an overpopulation of the plants rhinos eat.

• The population of animals that eat rhinos will increase.

Multiple Choice

Acid rain falls and changes the chemistry of the water in a lake. Click to enlarge the image.

Select the correct "number" order of the events shown at left, based on how each event affects the next.

• 6, 3, 1, 5, 4, 2

• 2, 3, 4, 1, 6, 5

• 1, 3, 2, 5, 4, 6

• 4, 2, 5, 6, 3, 1

The peppered moth can be either light or dark in color. Prior to the Industrial Revolution, when the factories were first built, the light colored moth was more common because it blended in with the bark of trees better. During the Industrial Revolution, the bark of the trees was turned black by the soot and the pollution. Now that the bark was darker, the light colored moths, which had been camouflaged before, were more likely to be eaten by birds.

The species adapted based on the changes in its ecosystem. An adaptation is a change in a trait or behavior to help an organism survive better in a specific ecosystem. The change in color of moths is an example of a physical adaptation.

Plants and animals can also adapt behaviorally. When there is a change in an ecosystem, organisms can adapt by moving to a new place, eating new foods, or changing the way they act. For example, a common behavioral adaptation of animals is hibernation. Bears have developed this adaptation to survive the winter when there is not enough food in their ecosystem.

Multiple Select

What will happen to the peppered moths as the bark of trees comes lighter again?

• The number of dark mothers will decrease.

• The number of light moths will increase.

• The number of dark moths will continue to increase.

• The number of light moths will continue to decrease.

If organisms cannot adapt to changes in their ecosystems, the species will not survive in that ecosystem. For example, the golden toad of Central America is considered to be the first animal to die out due to modern climate change. The next few slides will tell how the golden toad went extinct due to its inability to adapt.

Multiple Select

With their natural habitats shrinking or disappearing, hawks sometimes live in big cities. They nest on the ledges of tall buildings, eat pigeons and rodents, and find sources of water to drink. Which of these statements best describe these hawks?

• The hawks have adapted their behavior to live in a new ecosystem

• The hawks can find everything that they need to survive in the city.

• More and more hawks die because they cannot find a new habitat to live in.

Multiple Choice

A _________ adaptation is a change to the way an organism looks or to its appearance.

• physical

• behavioral

Multiple Choice

A __________ adaptation is a change to the way an organism acts.

• behavioral

• physical

Multiple Choice

Is this a behavioral or physical adaptation?

A species of bird develops a long skinny beak for picking up seeds.

• behavioral adaptations

• physical adaptations

Multiple Choice

Is this a behavioral or physical adaptation?

Butterflies migrate south for the winter.

• behavioral adaptations

• physical adaptations

Multiple Choice

Is this a behavioral or physical adaptation?

A Beaver builds a dam to protect itself from predators.

• behavioral adaptations

• physical adaptations

Multiple Choice

Is this a behavioral or physical adaptation?

A species of tree develops thick bark to keep water from evaporating from the trunk in a dry climate.

• behavioral adaptations

• physical adaptations

When a species is unable to adapt to changes in its ecosystem, all of the members of that species could die. When the last of a species dies, that species is extinct. Extinct species include dinosaurs, the woolly mammoth, the sabertooth tiger, and the dodo bird.

Animals can go extinct for many reasons. Dinosaurs went extinct after ash from an asteroid blocked out the Sun, making it impossible for plants to make their own food. The wooly mammoth and the saber-tooth tiger went extinct after the Earth's climate began to change at the end of the last ice age. The dodo bird went extinct due to overhunting by humans.

A species that is endangered is a species that is in danger of becoming extinct. Some examples of endangered species are mountain gorillas, panda bears, and tigers. All of these animals are endangered primarily due to humans destroying their natural habitats. Once a species is classified as endangered, programs are put inp place to try and save the species from extinction. These include breeding programs and habitat preservation.

A threatened species is a species with low numbers that could become endangered. Examples of threatened species are the gray wolf, the polar bear, and the manatee. Some animals on the list used to be endangered, like the gray wolf. After programs were put in place to save it, the gray wolf was upgraded from endangered to threatened. Other animals are on the threatened list because their numbers are decreasing.

Multiple Choice

There are fewer and fewer monarch butterflies alive. People keep killing the milkweed plant, which is the only plant where the monarch butterflies lay their eggs. Humans kill this plant because it is considered a weed. If this keeps happening, soon there will be no more monarch butterflies left. The monarch butterfly is ________.

• common

• endangered

• extinct

Multiple Choice

The number of red pandas in the world is decreasing. The forests that they live in are being cut down by humans to build houses, factories, and farms. If their habitat continues to be destroyed, they will become endangered. The red panda is ___________.

• endangered

• overpopulated

• threatened

• extinct

Multiple Choice

When the last member of a species dies, that species is ________.

• extinct

• danger

• thriving

• endangered

• threatened

Multiple Choice

A species that is endangered is a species that is in ________ of becoming extinct.

• extinct

• danger

• thriving

• endangered

• threatened

Multiple Choice

A _________ species is a species with low numbers that could become endangered.

• extinct

• danger

• thriving

• endangered

• threatened

Multiple Select

Rhinoceros are hunted for their horns. Humans have also taken over parts of their natural habitat. As of April 2015, there is only one male northern white rhinoceros left. There are only six northern white rhinoceros still alive. They are critically endangered. What can be done to keep this species from going extinct?

• They can be protected from being hunted for their horns.

• People can make sure that the rhinoceros that are alive have offspring.

• They can release the rhinoceros into the wild so they can adapt on their own.

• The habitats where they live can be made into conservation areas.

Animals can become endangered or extinct in a number ways. One way they can become endangered is when humans destroy their habitats. Many animals have become endangered or extinct due to human interaction with their environments.

Disease can also cause an animal to become threatened or endangered. If a new disease emerges and animals have no resistance to it, they can become endangered or threatened.

Humans sometimes hunt animals for food or other parts of the animal that are considered valuable. Some animals are endangered or threatened because humans have killed too many of the species. For example, some species of tuna are endangered because humans have overfished these populations. Rhinoceros are often hunted because their horns are considered valuable for medicinal purposes in some cultures.

Pollution can also cause species to become endangered or threatened. A common form of pollution is the pesticides that humans spray on crops. When it rains, these chemicals end up in the water. Once they are in the water, they can kill or poison the wildlife that lives there.

Multiple Select

What do you think happened to the population of bald eagles after DDT was banned in 1972?

• The bald eagle population continued to decrease

• The bald eagles' egg shells became thicker over time.

• The bald eagle population slowly started to increase.

• The bald eagle population was immediately restored to pre-DOT levels.

Multiple Select

Which of the following are ways that animals can become extinct?

Select all that apply.

• People over hunt them for food.

• Chemicals enter the environment and kill them.

• A new disease kills a large population of the species.

• New trees are planted where a forest was once cut down.

Scientists have learned a lot of things about animals that lived a long time ago and are now extinct by looking at their fossils. Fossils are remains, or traces, of plants or animals found in rocks. Fossils are formed when an animal is buried and the decomposition process is halted soon after death. Decomposition can be stopped if the animal freezes, dries out, or is covered with a substance like sand or tar.

Plants and animals can also be fossilized after they are quickly buried and the carbon in the organisms leaves an impression on the rock. Fossils can also be formed when the shape of a plant or animal turns into stone.

From fossils, scientists are able to learn about the types of animals that lived in that area long ago. They know this because the fossil remains in the area where the animal died. For example, they know there used to be water where this fossil of a fish was found.

From some fossils, scientists can tell if many of the species died at one time. They can tell if many of the same species died at once because they will find many fossils of the same organism in the same layer of rock. Scientists can use the fossils to hypothesize about the types of changes that occurred to kill so many of the same species at once.

In 2007, the fossilized remains of Lyuba were discovered. She is a baby woolly mammoth and the best-preserved specimen of her species ever found. Even though Lyuba died over 40,000 years ago, her remains still have hair!

Multiple Select

By examining the fossilized remains, scientists were able to find water and mud in her lungs and milk in her stomach. The scientists also found pollen in her stomach from the grass and flowers that were blooming when she died. What can you guess about how and when Lyuba died?

• She had recently drunk her mother's milk.

• She probably died in the spring.

• She fell into a muddy watering hole and drowned.

• She was crushed in an accident.

• She froze to death in the winter.

Multiple Choice

An adaptation is _________.

• waste that causes harm to land, water, or air.

• a trait or behavior to help an organism survive better in a specific ecosystem.

• when all of a species of animal dies

• the interaction between plants and animals in an area

Multiple Choice

What is the definition of extinct?

• all of the members of a species that have died out

• plants and animals are interacting

• remains or traces of plants or animals found in rocks

• a species of animal that has low numbers

Multiple Choice

A species is endangered when ___________.

• a species is in danger of becoming extinct

• plants and animals are interacting in an area

• there is a lot of waste that causes harm to land, water, or air

• a species has low numbers, but is not about to become extinct

Multiple Choice

If a species is threatened, it is __________.

• a species with low numbers that could become endangered

• producing a lot of waste that causes harm to land to land, water, or air

• a species that is not in danger of becoming extinct

• remains or traces of plants or animals found in rocks

Multiple Choice

What is a fossil?

• an animal that is not in danger of becoming extinct

• remains or traces of plants or animals found in rocks

• the interaction of plants and animals in an area

• waste that can cause harm to air, land, and water

Multiple Choice

When _______ changes to an ecosystem occur, there can be major effects on ecosystems. Species often have to ________ to these changes, move away, or die.

• extinct; fossils

• major; adapt

• adapt; major

• threatened; major

In the 1960s, alligators had nearly disappeared in the United States due to habitat destruction and being hunted for their skins. In 1973, Congress passed the Endangered Species Act to protect endangered species. After the act was passed, the number of alligators in the United States dramatically increased.

Multiple Select

The alligator was removed from the endangered species list in 1987. Which of the following were probably a result of the Endangered Species Act?

Check all that are true.

• People created conservation parks to help keep alligators safe and to help them breed.

• People were allowed to keep hunting alligators for their skin.

• People began to protect the alligators' habitats.

• People had to stop hunting alligators for their skin.

Multiple Select

Humans develop a chemical that kills wasps. A town sprays the chemical, and all but a few wasps are killed. Those wasps were immune to the chemical. Over time, fewer and fewer wasps are killed by the chemical. Which of the following statements are true?

• The wasps are adapting.

• Humans will have to develop a new chemical if they want to kill the wasps.

• The wasps will go extinct.

• More and more wasps will become immune to the chemical.

Multiple Choice

As of April 2015, there are only 880 mountain gorillas left in the world. The mountain gorilla species is endangered. This is because humans have started to take over more and more of their habitat. What will happen if the population of mountain gorillas continues to decrease?

• There will be more gorillas.

• They will become extinct.

• They will become threatened.

• They will be fossilized.

Multiple Choice

In the 1960s, parts of the coast of Florida were flooded in order to control mosquitoes, and other parts were dried out in order to build highways. In 1990, the dusky seaside sparrow, a bird that lived mainly on the Florida coastline, was declared extinct. What is the most likely cause of this sparrow's extinction?

• Their habitat was destroyed, so they had nowhere to live or have offspring.

• They adapted and moved somewhere else.

• Humans over-hunted them for food.

• They were killed by predators.

Multiple Choice

How can scientists learn about the plants and animals that used to live in an ecosystem long ago?

• Most of the same plants and animals that live in ecosystems now lived there long ago.

• Scientists can look at the ecosystem that is there today and hypothesize about what the area used to look like.

• Scientists already know about all plants and animals that have ever gone extinct.

• Scientists can use fossils to learn more about extinct species that used to live in a certain area.

Multiple Select

How can removing a species from an ecosystem cause a major change?

Check all that are true.

• The population of the animals that eat the species will decrease.

• The population of the plants or animals the species eats will decrease.

• The population of the animals that eat the species will increase.

• The population of the plants or animals the species eats will increase.