The picture shows a koala bear in Australia. The koala bear eats only a specific type of leaf from eucalyptus trees. Eucalyptus trees are being decreased by drought, forest fires, and deforestation. What does the scientific theory of evolution suggest about the future of the koala bear?

A. The koala bear population may increase because the strongest will find food and reproduce.

B. The koala bears may become extinct if they are unable to adapt to finding new food sources.

C. The koala bear population will stay stable as long as they stay in geographic isolation.

D. The koala bears' genes will change immediately to allow them to survive on less food

What variation of an individual owl in an owl population would make the individual most likely to survive in an environment where the owl's prey is scarce?

A. having better eyesight to spot prey more easily

B. having shorter wings to increase flight speed

C. having bigger nests to support more offspring

D. having fewer feathers to increase agility

Which statement is most likely correct about the peppered moth population after the Industrial Revolution?

A. The dark-colored peppered moth population was larger after the Industrial Revolution.

B. The light-colored peppered moth population was larger after the Industrial Revolution.

C. Both moth populations increased after the Industrial Revolution.

D. Both moth populations decreased after the Industrial Revolution.

Why did the moth population change after the Industrial Revolution?

A. because the soot allowed the dark moths to blend into their environment

B. because the soot allowed the light moths to stand out to attract more prey

C. because the soot prevented the moths from having a clean place to breed

D. because the soot provided a carbon-rich energy source for the moths to absorb

The rat snake is found in a wide array of environments. They are found in woods, along the coast, in cities, and in mountains. They eat rats, birds, mice, and squirrels. Rat snakes also have varied appearances. They are gray, yellow, black, and mixes of these colors, depending on where they live. Which of the following explains the differences in colors of the rat snake?

A. The rat snakes' colors are adaptations caused by natural selection, which help them blend into their environment and hunt for food.

B. The rat snakes' colors vary because they eat different foods in different environments that make their skin color change.

C. The rat snakes' colors vary as a result of artificial selection, which allows them to choose the best color suited for their environment.

D. The rat snakes' colors vary because they have the ability to change their color like a chameleon in response to a changing environment.

The picture shows a giraffe eating leaves off of a tree. Which of the following variations would best help individuals in a population of giraffes outlive the other giraffes?

A. having the longest necks to reach food at higher levels than the others

B. having the brightest fur to blend into the environment, avoiding predators

C. having the most spots to be able to attract more mates for reproduction

D. having the sharpest teeth to break down plant matter, absorbing more nutrients

The picture is of the Raphus cuculatus, commonly known as the dodo bird. Large flightless birds, the dodos lived on the island of Mauritius in the Indian Ocean. The last known dodo bird was seen in the 17th century, about 100 years after humans first discovered them. What is the most likely reason why the dodo bird is now extinct?

A. They developed aggressive behaviors, with fights that often led to death.

B. All were captured and put in captivity, where they could not survive.

C. All failed to adapt to the changes in their external environment.

D. They grew functional wings and evolved into another species.

Variation in which characteristic would best help bison survive a harsh winter?

A. fur thickness to insulate the bison from the cold weather B. hoof size to be able to migrate to warmer temperatures C. leg length to be able to catch prey more easily

D. hearing quality to be able to sense predators faster

A mouse population has various traits within its members. The mice have different fur colors, speeds at which they run, and different tolerances to a lack of food. If a new predator is introduced to the environment, which mice would be most likely to survive?

A. mice that stand out in their environment

B. mice with a low tolerance for lack of food

C. fast mice that blend into their environment

D. slow mice with a high tolerance for lack of food

According to Darwin's theory of natural selection, the individuals that tend to survive are those that have

A. the greatest number of offspring.

B. variations best suited to environmental conditions.

C. characteristics that plant and animal breeders value.

D. characteristics their parents acquired by use and disuse.

Evidence that life on Earth has changed over time is buried within the Earth. What is this evidence?

A. embryology

B. fossils

C. sedimentary rock

D. magma

Prior to the Industrial Revolution in England, the light version of the moth was the most common, and the dark version was mostly unknown. As a result of pollution caused by the burning of coal, the population of dark moths increased so that they were the dominate form in most areas by the end of the nineteenth century.'

Which statement most likely explains the rapid evolution of dark moths?

A. Dark moths were able to camouflage themselves and hide from predators due to soot covering the trees.

B. Dark moths were able to fly faster in the polluted air to escape predators that ate moths.

C. Dark moths were able to out-compete the light moths for food by hunting during the day.

D. Dark moths were able to locate mates for reproduction more easily than light moths.

A poison dart frog's bright colors tell predators that the frog is poisonous. The picture shows a poison dart frog. Not all brightly colored frogs are poisonous.

Which statement best explains why natural selection might favor bright colors in frogs that are not poisonous?

A. Bright colors help frogs catch their prey.

B. Bright colors make it easier for frogs to find mates.

C. Bright colors make frogs more visible to their predators. D. Bright colors mimic poisonous frogs so predators avoid them.

Every year, adult salmon swim upstream to a spawning area. To get to the area, salmon have to swim against strong currents for a long time. Only the strongest salmon successfully complete the journey. What concept is represented in this example?

A. mutualism

B. climax community

C. succession

D. survival of the fittest

Paleontologists have discovered many fossils that document the evolution of birds from dinosaurs that roamed Earth long ago. What does the fossil record tell us about this change?

A. All reptiles once possessed the ability to fly.

B. It occurred immediately after a meteor struck Earth.

C. It has reversed itself many times throughout history.

D. It happened slowly over a long period of time

The fossil record is assembled by combining the data scientists learn from the fossils they study. What does the fossil record allow scientists to develop?

A. a record of how Earth formed and changed over time

B. an understanding of the forces operating in nature

C. a complete history of all living things that have existed

D. a timeline showing the evolution of life from earlier species