Question

What are sand dunes,​

Answer 1

Explanation:

A dune is a mound of sand formed by the wind, usually along the beach or in a desert. Dunes form when wind blows sand into a sheltered area behind an obstacle. Dunes grow as grains of sand accumulate. Every dune has a windward side and a slipface.

Answer 2

Explanation:

Microbes are just single cells with no organelles and no nuclei to package their DNA. Something revolutionary happened as microbes began living inside other microbes, functioning as organelles for them. Mitochondria, the organelles that process food into energy, evolved from these mutually beneficial relationships.

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