The ovum is defined as the female sex cell, or egg, essential for reproduction. It is produced in the ovaries and plays a key role in the fertilization process. Other provided definitions do not accurately reflect this term. ;
The ovum is the female sex cell, or egg, crucial for reproduction. It is produced in the ovaries and is necessary for fertilization with sperm. Therefore, the correct answer is option A: female sex cell, or egg.
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