Earth History & Adaptations/Genetics Schoolnet

Which characteristic of an index fossil makes it MOST USEFUL in relative dating of rocks an other fossils?

• They are found only in a few areas.
• Their existence on Earth was brief.
• They are preserved in perfect condition.
• They are usually found in certain kinds of rock.

An undisturbed rock geologic column has a fossil of a reptile species in the lowest rock layer, an index fossil that was present 1 million years ago in the middle rock layer and a fossil of a clam species in the topmost rock layer. Which conclusion is MOST LIKELY correct?

• The clam species is older than one million years old.
• The reptile species is older than one million years old.
• The index fossil is older than the reptile species fossil
• The clam species fossil is older than the reptile species fossil.

Which BEST describes a fossil that helps determine the relative age of a rock layer?

• trace fossil
• index fossil
• radioactive fossil
• unconformity fossil

Fossils of the fern Glossopteris have been found in the continents of South America, Africa, Asia and Antarctica. The seeds of this fern were too small to be dispersed by wind. Which is best indicated by the presence of Glossopteris fossils on these continents?

• Golssopteris was versatile enough to adapt to all climates.
• The landmasses were joined together in prehistoric times.
• Fossils were much better preserved in the southern continents.
• The northern climate regions wer e not suitable for plant growth.

What evidence do fossils provide geologists about the history of the Earth?

• Living things have remained the same over time.
• Environmental conditions have changed over time.
• The amount of water on Earth has changed over time. 
• Environmental conditions have remained the same over time.

If a fault cuts through multiple layers of rock, which is most likely true?

• An earthquake happened after the layers formed.
• An earthquake happened before the layers formed.
• An earthquake happened at the same time the layers formed.
• The timing of the earthquake is unrelated to when the layers formed.

Which would most likely cause an entire species to become extinct?

• disease
• predators
• competition for food
• limited genetic variation

Archaeologists are working in a previously undisturbed dig site. A fossil isfound at a depth of 5 meters, and a second fossil is found at a depth of20 meters. When comparing the two fossils, which conclusion can the archaeologists most likely make?

• The two fossils are from the same species of organism.
• The fossil found at 5 meters is older than the fossil found at 20 meters.
• The two fossils were from organisms which evolved from the same ancestral species.
• The fossil found at 5 meters is more similar to present-day organisms than the fossil found at 20 meters.

Why is genetic variation within a species important for the survival of the species?

• It will likely result in larger individuals in the species.
• It will likely result in the species becoming predators.
• It will likely result in more intelligent individuals in the species.
• It will likely result in individuals in the species being able to adapt to their environment.

Bird A can blend in with its environment, fly far, and eat a variety of nuts and seeds. Bird B is an unusually colored, weak flyer that eats only one type of seed regularly. Which statement is most likely true?

• Bird B is a powerful predator.
• Bird A will be easily preyed upon by larger birds.
• Bird A will eventually thrive and reproduce due to strong genetic variation.
• Bird B will eventually thrive and reproduce because of specialized features.