_____ Is Caused by the Presence of an Extra Copy

question 123

Multiple Choice

_____ is caused by the presence of an extra copy of chromosome 21.

• A) Down syndrome
• B) Hemophilia
• C) Huntington's disease
• D) Sickle-cell anemia

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Definitions:

Crust Thickness

The measure of the depth or the vertical extent of the Earth's crust, varying between oceanic and continental regions.

Rule of Thumb

A widely used guideline or principle that is not strictly accurate or reliable for every situation but provides a good general estimate.

Isostatic Rebound

Uplifting caused by the removal of weight on top of the crust, as when an ice sheet melts away or when erosion strips material off the top of a thick crustal root of a mountain.

Ice Sheet

A large mass of glacier ice that covers an area of over 50,000 square kilometers, often found in polar regions.