History of Life - Fossil Record

Open Ended

What are some ways scientists gather evidence about the origin of life on Earth?

Multiple Choice

Why is it important for scientists to study the history of life and the fossil record?

• To understand how life has changed over time

• To predict future weather patterns

• To learn about the structure of atoms

• To improve computer technology

Multiple Choice

Why did early attempts to estimate Earth's age using sedimentary rocks fail?

• The techniques were not accurate enough.

• There were no fossils in sedimentary rocks.

• Sedimentary rocks are too young.

• Scientists did not know about isotopes.

Multiple Choice

What is one method scientists use to determine the age of rocks and fossils?

• Radioactive dating

• Carbonation

• Evaporation

• Photosynthesis

Multiple Select

Which of the following statements about isotopes are correct?

• Isotopes have the same number of protons.

• Isotopes have different atomic masses.

• Isotopes have the same number of neutrons.

• Isotopes have the same atomic number.

Multiple Choice

What is the main difference between stable and radioactive isotopes?

• Radioactive isotopes undergo decay, releasing particles or energy.

• Stable isotopes have more protons than neutrons.

• Radioactive isotopes have the same atomic mass as stable isotopes.

• Stable isotopes are only found in living organisms.

Fill in the Blanks

The amount of time it takes for one-half of a sample of isotope to decay is called its

.

Multiple Choice

Which isotope of carbon is radioactive and used in dating ancient biological materials?

• Carbon-12

• Carbon-13

• Carbon-14

• Carbon-16

Fill in the Blanks

The half-life of carbon-14 is

years.

Multiple Choice

Why can't potassium-40 and uranium-238 be used to date most fossils directly?

• They are unstable isotopes.

• Their half-lives are too short.

• Living organisms do not incorporate these isotopes into their bodies.

• They are only found in water.

Fill in the Blanks

If a fossil is found in a particular rock layer, it can be assumed that the

has an age relative to that rock layer.

Fill in the Blanks

The oldest sedimentary rock layers are found at the

, while the most recent layers are found closer to the surface.

Multiple Choice

What does relative dating help scientists determine about fossils?

• The exact age of a fossil in years

• The placement of a fossil in relation to other fossils

• The chemical composition of a fossil

• The environment where a fossil was found

Fill in the Blanks

Many of the organisms that were once common on Earth are now

.

Multiple Choice

What does the fossil record show about the history of life on Earth?

• There have been great changes in the kinds of organisms that dominated life at different times.

• All organisms have remained the same over time.

• Only plants have changed over time.

• Fossils only show extinct organisms.

Multiple Select

Which of the following are reasons why the fossil record is considered incomplete?

• Many organisms did not die in the right place at the right time to be preserved as fossils.

• Many fossils have been destroyed by geologic processes.

• All fossils have been found.

• Only a fraction of the fossils have been found.

Multiple Choice

Which characteristic increases the likelihood that a species will be represented in the fossil record?

• Having hard shells or skeletons

• Being rare and short-lived

• Living only in one small area

• Being soft-bodied