1. the fossils of an extinct mammal, ambulocetus, show that it had four legs so it had the ability to walk on land. it also had a long tail thought to it in swimming
what kind of evidence makes ambulocetus the probable ancestor of modern whales?
a. behavior b. bones c. coloring d. diet

2. a science museum displays a flat rock that contains a fossil imprint of a type of plant called a fern. beside the rock is a drawing of a modern fern. what evidence can you conclude from comparing the two ferns?

fossil fern modern fern
a. ferns are eaten by omnivores.
b. ferns grow in every environment.
c. ferns have changed little over time.
d. ferns require sun for photosynthesis.

3. when charles darwin first observed the finches on the galapagos islands, he noticed that the beaks of the birds on each island were different. the drawings below show four different beaks.

what is a possible explanation for the difference in the birds’ beaks?

a. adaptation to different food sources
b. adaptation to different temperature ranges
c. ability to attract different mates
d. ability to protect from different predators

4. a certain characteristic such as color of fur may an individual organism survive and reproduce. the characteristic is then inherited by its offspring. over time the characteristics of this kind of organism in the population change. what is the scientific name for this process?

a. natural selection
b. petrification
c. selective genetics
d. uniformitarianism

5. a farmer wanted to find out if the number of plants per field would impact the final number of plants that survived in a field. fields a, b, and c were the same size with the same type of soil. they also received the same amount of light and water.
number of plants at the beginning of the season number of plants at the end of the season
field a 500 450
field b 750 600
field c 1,000 300

what is a possible explanation for the decrease in the final number of plants in field c?

a. only plants with specific traits survived.
b. plants with deeper roots received more water.
c. plants whose seeds were carried by wind survived.
d. too many plants in a small area competed for nutrients.

6. a forest ecosystem contains many small mammals such as chipmunks and mice that live in the brown leaves on the forest floor. imagine that a population of white mice was introduced into the forest environment. why would there be no white mice found in the forest one year later?
a. the mice could not find water.
b. the mice could not find shelter.
c. the mice could not find and store food.
d. the mice could not hide from predators.

7. bacteria are microscopic organisms that reproduce rapidly and often cause disease. antibiotics are drugs given to people to cure bacteria-caused diseases. since the 1950s, scientists have observed that antibiotics cannot kill many kinds of bacteria. what best explains the reason why antibiotics are less effective now?

a. people today do not take antibiotics as directed by doctors.
b. antibiotics used today are weaker drugs than those used in the past.
c. the genes of some kinds of bacteria make them resistant to antibiotics.
d. doctors have increased the testing of patients for diseases caused by bacteria.

8. zebras are animals that live on the grasslands of africa. lions prey on zebras, especially the young
which of the following would be an example of “survival of the fittest” among zebras

a. being able to eat many kinds of food
b. being able to run very fast
c. having wider stripes
d. having shorter legs
9. the golden toad was a small, shiny toad that was abundant in a tropical rain forest in costa rica. the toads laid eggs in small pools of water. when the tadpoles hatched, they swam in the water until they became adult toads. between 1987 and 1989 a dramatic drop in rainfall occurred in the area. not a single toad has been seen since 1989.
what is the most likely reason that the golden toad is now believed to be extinct?

a. predators ate all the toads.
b. the toads could not find mates.
c. the toads moved to another area.
d. lack of rain interrupted the life cycle of the toads.

10. crickets living in caves eat fungi and often only one type of insect. which of the following would most likely result in the cricket becoming extinct over a long period of time?

a. the cricket produces many offspring with unique traits and changes its diet.
b. the cricket produces few offspring with no new traits and changes its diet.
c. the cricket produces many offspring with unique traits and does not change its diet.
d. the cricket produces few offspring with no new traits and does not change its diet.

short response

11. darwin’s observations of the unique characteristics of animals on each of the galápagos islands led to his development of theory of evolution by natural selection. how do observations lead to the development of a scientific theory?