Instructions: Identify the Terms and Briefly State Their Historical Significance

question 78

Essay

Instructions: Identify the terms and briefly state their historical significance.
The Great Wall

---

Definitions:

Fraternal Twins

Siblings born from the same pregnancy but developed from separate eggs fertilized by different sperm, making them genetically distinct from each other.

Identical Twins

Siblings born from the same pregnancy who share identical genetic material because they were created from the same egg and sperm.

Bipolar Disorder

A psychological disorder defined by significant shifts in mood, including periods of intense euphoria (mania or hypomania) and profound sadness (depression).

Sodium Ions

Positively charged ions of sodium, essential for the electrical signals in the nervous system and for regulating body fluids.