Origin and Evolution of Earth - Practice Test 2

Attempt the quiz above first, then review every question with its correct answer and a short explanation below.

1. Q1.Modern humans (Homo sapiens) evolved during which Epoch?

   • A.Miocene
   • B.Pliocene
   • C.Pleistocene✓ Correct Answer
   • D.Holocene

   Explanation: Modern humans evolved during the Pleistocene epoch.

2. Q2.The current geological epoch we live in is:

   • A.Pleistocene
   • B.Holocene✓ Correct Answer
   • C.Oligocene
   • D.Eocene

   Explanation: We are currently in the Holocene epoch, which began about 11,700 years ago.

3. Q3.Pangaea began to break apart during which Period?

   • A.Permian
   • B.Triassic✓ Correct Answer
   • C.Jurassic
   • D.Cretaceous

   Explanation: Pangaea began to break up in the Late Triassic period.

4. Q4.Which Era is called the 'Age of Mammals'?

   • A.Cenozoic✓ Correct Answer
   • B.Mesozoic
   • C.Paleozoic
   • D.Proterozoic

   Explanation: The Cenozoic Era is characterized by the dominance of mammals.

5. Q5.The Himalayas were formed during which Era?

   • A.Paleozoic
   • B.Mesozoic
   • C.Cenozoic✓ Correct Answer
   • D.Precambrian

   Explanation: The Himalayas formed in the Cenozoic Era (Tertiary period) due to plate collision.

6. Q6.Density of the Earth ___ as we go deeper into the interior.

   • A.Increases✓ Correct Answer
   • B.Decreases
   • C.Remains same
   • D.Fluctuates

   Explanation: Density increases with depth due to pressure and heavier materials like iron/nickel.

7. Q7.The innermost layer of the Earth is called:

   • A.Crust
   • B.Mantle
   • C.Core✓ Correct Answer
   • D.Lithosphere

   Explanation: The Core is the innermost layer.

8. Q8.The Core of the Earth is mainly composed of:

   • A.Silica and Aluminum
   • B.Silica and Magnesium
   • C.Nickel and Iron✓ Correct Answer
   • D.Basalt and Granite

   Explanation: The Core is often referred to as NIFE (Ni - Nickel, Fe - Ferrous/Iron).

9. Q9.The discontinuity between the Crust and the Mantle is called:

   • A.Gutenberg Discontinuity
   • B.Mohorovicic Discontinuity✓ Correct Answer
   • C.Lehman Discontinuity
   • D.Conrad Discontinuity

   Explanation: The Moho (Mohorovicic) discontinuity separates the Crust from the Mantle.

10. Q10.The discontinuity between the Mantle and the Core is called:

    • A.Mohorovicic Discontinuity
    • B.Gutenberg Discontinuity✓ Correct Answer
    • C.Repetti Discontinuity
    • D.Conrad Discontinuity

    Explanation: The Gutenberg discontinuity separates the Mantle from the Outer Core.

11. Q11.Which layer of the Earth is in a liquid state?

    • A.Inner Core
    • B.Outer Core✓ Correct Answer
    • C.Mantle
    • D.Crust

    Explanation: The Outer Core is liquid, which generates Earth's magnetic field.

12. Q12.The lithosphere consists of:

    • A.Crust only
    • B.Mantle only
    • C.Crust and Upper Mantle✓ Correct Answer
    • D.Core and Mantle

    Explanation: The Lithosphere includes the Crust and the rigid uppermost part of the Mantle.

13. Q13.The semi-fluid layer below the lithosphere on which plates move is:

    • A.Asthenosphere✓ Correct Answer
    • B.Mesosphere
    • C.Barysphere
    • D.Exosphere

    Explanation: The Asthenosphere is the viscous, plastic-like layer in the upper mantle.

14. Q14.SIAL usually refers to which part of the Earth's crust?

    • A.Oceanic Crust
    • B.Continental Crust✓ Correct Answer
    • C.Lower Crust
    • D.Mantle

    Explanation: Continental Crust is rich in Silica and Aluminum (SIAL).

15. Q15.SIMA refers to:

    • A.Silica and Magnesium✓ Correct Answer
    • B.Silica and Manganese
    • C.Silver and Magnesium
    • D.Silicon and Mercury

    Explanation: SIMA (Silica + Magnesium) constitutes the Oceanic Crust.

16. Q16.Which element is most abundant in the Earth's Crust?

    • A.Iron
    • B.Oxygen✓ Correct Answer
    • C.Silicon
    • D.Aluminum

    Explanation: Oxygen (~46%) is the most abundant element in the crust, followed by Silicon.

17. Q17.Which element is most abundant in the Earth as a whole?

    • A.Oxygen
    • B.Iron✓ Correct Answer
    • C.Silicon
    • D.Nickel

    Explanation: Iron (~35%) is the most abundant element in the entire Earth (due to the core).

18. Q18.The mean radius of the Earth is approximately:

    • A.6371 km✓ Correct Answer
    • B.3200 km
    • C.12700 km
    • D.5000 km

    Explanation: The Earth's radius is approximately 6371 km.

19. Q19.The theory of Continental Drift was proposed by:

    • A.Harry Hess
    • B.Alfred Wegener✓ Correct Answer
    • C.Arthur Holmes
    • D.Morgan

    Explanation: Alfred Wegener proposed Continental Drift in 1912.

20. Q20.According to Wegener, the supercontinent was named:

    • A.Panthalassa
    • B.Pangaea✓ Correct Answer
    • C.Laurasia
    • D.Gondwanaland

    Explanation: Pangaea was the supercontinent, and Panthalassa was the superocean.