Reading rock layers and the history of life

Grade 6 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   “not to scale” Ari sketches a cliff with four flat, undisturbed rock layers, A on top down to D at the bottom. Which layer is the oldest?

   • B, since it is the thickest
   • Each layer is the same age
   • D, at the bottom
   • A, at the top
2. 2.

   Layer B with fish-shaped fossils above layer C with shell-shaped fossils; the layers are flat. Layer B has fish fossils, and layer C just below it has shell fossils. The layers are flat and undisturbed. Which fossils does Kira say are older?

   • Both are the same age
   • The shells in layer C
   • The fish in layer B
   • Whichever fossil is bigger
3. 3.

   Luz is making a museum label. Which is the best meaning of the word fossil?

   • A rock that wind carved into an animal shape
   • Remains or traces of a living thing kept in rock
   • A living thing that turned to stone overnight
   • Any very old rock
4. 4.

   Low layers hold fossils of sea creatures unlike any living today; high layers hold fossils like today's clams. What does Milo conclude?

   • Life on Earth has changed over time
   • The upper fossils are the older ones
   • Today's clams were the first life
   • The kinds of life stayed the same
5. 5.

   Noah is making a time-line poster. Which list puts the three eras in order, oldest first?

   • Mesozoic, Paleozoic, Cenozoic
   • Paleozoic, Cenozoic, Mesozoic
   • Paleozoic, Mesozoic, Cenozoic
   • Cenozoic, Mesozoic, Paleozoic
6. 6.

   In which era did dinosaurs (other than birds) live, according to Pia's time line?

   • The Mesozoic
   • In each era, right up to today
   • The Cenozoic, alongside early people
   • The Paleozoic, before any fish
7. 7.

   Three picture cards (trilobite, dinosaur, early person) next to a blank time line from older to today. Ren puts three fossil cards on the time line: trilobites, dinosaurs and early people. Which order is right, oldest first?

   • Trilobites, then dinosaurs, then people
   • Trilobites, then people, then dinosaurs
   • People and dinosaurs together, then trilobites
   • Dinosaurs, then people, then trilobites
8. 8.

   A blank time line from Earth's start to today. About how old is the Earth, according to the USGS page Tala is reading?

   • About 4.5 billion years
   • About 45,000 years
   • About 100 billion years
   • About 4.5 million years
9. 9.

   How did scientists work out Earth's age, as Zee reads on the USGS page?

   • By counting the layers in one cliff
   • By measuring radioactive elements in old rocks and meteorites
   • By guessing from how tall mountains are
   • By judging how old the oldest fossils look
10. 10.

    A long time line from Earth's start to today, with a blank box at the right end. Esme compares how long people have been around with Earth's whole history. Which fits?

    • About half of Earth's history
    • Almost the whole of Earth's history
    • A tiny sliver at the very end
    • Ever since Earth formed