Answer with Explanation:
Heredity and environment may play a role in connection to <em>birth defects</em>.
For example, when it comes to heredity, some genes can be transferred to children. An example of this is the <em>"sickle cell disease." </em> If parents transfer two of these genes to the child, then the child will most likely inherit the disease.
Another example, when it comes to <u>environment</u>, the exposure of a mother to certain factors like <em>radiation, drugs (teratogens), alcohol, etc</em><em>.</em> may result to birth defects in children. When it comes to alcohol, mothers who have been drinking alcohol while pregnant will deliver a baby with <em>"fetal alcohol syndrome."</em> The baby with this syndrome will have problems with his <em>learning ability, physical disproportions (esp. the face), will be hyperactive, et</em>c.