Question 1

Which of the following best describes macroevolution?

Accepted Answer

Broad changes in species composition brought about through environmental change or evolutionary novelty.

Question 2

Which of the following is an example of a macroevolutionary event?

Accepted Answer

The emergence of mammals after the extinction of dinosaurs.

Question 3

What is the primary method used to determine the absolute age of a fossil?

Accepted Answer

Radiometric dating using unstable, radioactive isotopes.

Question 4

Why is radiometric dating more reliable than relative dating for determining the age of rocks?

Accepted Answer

It measures the decay of radioactive isotopes, providing an absolute age.

Question 5

A sample contains 25% of its original Carbon-14. If the half-life of Carbon-14 is 5,700 years, how old is the sample?

$N = N_0 	imes (\frac{1}{2})^{t/t_{1/2}}$

Accepted Answer

11,400 years

Question 6

Which statement about radioactive isotopes is correct?

Accepted Answer

They emit subatomic particles in a predictable manner as they decay.

Question 7

Why is Carbon-14 useful for dating relatively recent fossils, but not very old rocks?

Accepted Answer

Carbon-14 has a relatively short half-life, so it decays away in older samples.

Question 8

Which of the following best explains how scientists use rock layers to reconstruct Earth's history?

Accepted Answer

Layers of rock occur sequentially, representing a pattern of geological change over time.

Question 9

A scientist finds a fossil in a rock layer below a layer containing stromatolites. What can be inferred about the fossil's age?

Accepted Answer

It is older than 3.5 billion years.

Question 10

Which event marks the beginning of the Phanerozoic eon?

Accepted Answer

The Cambrian explosion.

Question 11

Which of the following is true about stromatolites?

Accepted Answer

They are fossilized films created by bacterial colonies.

Question 12

If Uranium-238 has a half-life of 4.5 billion years, how much of an original 100g sample would remain after 9 billion years?

$N = N_0 	imes (\frac{1}{2})^{t/t_{1/2}}$

Accepted Answer

25g

Question 13

Which of the following statements about the Precambrian is correct?

Accepted Answer

It includes everything prior to the Phanerozoic eon.

Question 14

Which eon saw the evolution of the first multicellular organisms?

Accepted Answer

Proterozoic

Question 15

A fossil is found in a rock layer that is determined to be 2.5 billion years old. Which eon does this fossil most likely belong to?

Accepted Answer

Archean

Question 16

Which of the following best describes the process of using radioactive isotopes to date rocks?

Accepted Answer

Measuring the ratio of stable to unstable isotopes to determine the time since the rock formed.

Question 17

Which of the following is a key adaptation that contributed to macroevolutionary change?

Accepted Answer

The development of wings in insects.

Question 18

If a radioactive isotope has a half-life of 1,000 years, how much of a 40g sample will remain after 3,000 years?

$N = N_0 	imes (\frac{1}{2})^{t/t_{1/2}}$

Accepted Answer

5g

Question 19

Which of the following is NOT a method used to determine the relative age of fossils?

Accepted Answer

Radiometric dating of isotopes.

Question 20

Which of the following best explains why some isotopes are radioactive?

Accepted Answer

They have an unstable combination of protons and neutrons.

Macroevolution, Fossil Dating, and Earth's History: Study Notes for General Biology

Study Guide - Practice Questions