Why Would Sand Be Deposited Behind a Small Island to Form

question 69

Multiple Choice

Why would sand be deposited behind a small island to form a spit or tombolo?

• A) The onshore current from one direction piles up sand here.
• B) Waves refract around the island and the wave energy is dissipated on the island, allowing quiescent water behind, and sand drift to accumulate behind the island.
• C) The island protects the coast from rip currents, preserving the sand.
• D) The tidal affects are trivial behind the island, so the sand is not swept away.

---

Definitions:

Deoxyribose

Pentose sugar lacking a hydroxyl (—OH) group on carbon-2′; a constituent of DNA.

Hydroxyl Group

A functional group consisting of an oxygen atom bonded to a hydrogen atom (-OH), which is found in alcohols and many other organic molecules.

Ribose

The 5-carbon sugar present in RNA and in important nucleoside triphosphates such as ATP.

Leader Sequences

Short sequences of amino acids at the beginning of the synthesis of a protein that signal where in the cell it should be localized.