Teratology is the branch of biology that deals with the study of birth defects and developmental abnormalities.

Autism spectrum disorder is a neurodevelopmental disorder, not a birth defect.

Genetic factors, such as chromosomal abnormalities and gene mutations, are the leading cause of birth defects.

Alcohol consumption, smoking, and exposure to radiation are all environmental factors that can increase the risk of birth defects.

A Mendelian disorder is a birth defect that is caused by a single gene mutation.

Down syndrome is an example of a chromosomal disorder, caused by an extra copy of chromosome 21.

A multifactorial disorder is a birth defect that is caused by a combination of genetic and environmental factors.

Fetal alcohol syndrome is an example of a teratogenic disorder, caused by alcohol consumption during pregnancy.

The critical period for development of the heart is 3-8 weeks of gestation.

Patent ductus arteriosus is a congenital heart defect that usually closes shortly after birth.

Spina bifida is the most common type of neural tube defect.

Bilateral cleft palate is a rare type of cleft lip and palate.

Down syndrome is the most common type of chromosomal disorder.

Autism spectrum disorder is a neurodevelopmental disorder, not a multifactorial disorder.

Prenatal care, genetic counseling, and healthy lifestyle choices can all help to prevent birth defects.