What Is True of the Cambrian Explosion

question 30

Multiple Choice

What is true of the Cambrian explosion?

• A) There are fossils of animals in geological strata that are older than the Cambrian explosion.
• B) Only the fossils of microorganisms are found in geological strata older than the Cambrian explosion.
• C) The Cambrian explosion is evidence for the instantaneous creation of life on Earth.
• D) The Cambrian explosion marks the appearance of filter-feeding animals in the fossil record.

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Definitions:

Bromide Ion

The bromide ion is a negatively charged ion (Br-) that is formed when a bromine atom gains an electron.

Ionic Compound

A chemical compound composed of ions held together by electrostatic forces termed ionic bonding, generally formed between metal and non-metal ions.

Calcium

A soft gray alkaline earth metal, symbol Ca, essential for living organisms, particularly in cell physiology and bone formation.

Oxygen

Oxygen, a diatomic gas with the molecular formula O2, is critical for respiration in living organisms and supports combustion.