How does a sand dunes change earths surface

They act as barriers whereby wind deposits its load to  come up with major land forms in the desert.

Explanation:

Sand dunes retain  the load  that arises as a result of  erosion processes ,and disposition.

Wind deposits con form hills and sand sheets .

An example of this is in California , whereby Sand dunes make up to 25 %  of the land-forms in the arid areas .

Sand dunes can also influence the formation of oases , as a result of wind action.

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answer; i believe the correct answer is (sporophyte);