Final answer:
Anencephaly is a condition where the skull is present but the brain is absent. It is a type of neural tube defect that occurs during embryonic development and is usually fatal shortly after birth or during pregnancy.
Step-by-step explanation:
Anencephaly is a condition where the skull is present but the brain is absent. It is a type of neural tube defect that occurs during embryonic development. In anencephaly, the neural tube fails to close properly, resulting in the absence of a major portion of the brain and skull. The condition is usually fatal shortly after birth or during pregnancy.