LIFE SCIENCE

Detailed explanation-1: -Smoking, drinking alcohol, or taking certain “street” drugs during pregnancy. Having certain medical conditions such as uncontrolled diabetes before or during pregnancy. Taking certain medicines. Being deficient in folic acid.

Detailed explanation-2: -A developing embryo or fetus (center) can be exposed to numerous environmental factors. These factors can interact with the genetic susceptibility of the developing embryo or fetus to alter the outcome of development. There is growing evidence that chemicals originally considered safe can cause developmental defects.

Detailed explanation-3: -A teratogen is any agent that causes an abnormality following fetal exposure during pregnancy. Teratogens are usually discovered after an increased prevalence of a particular birth defect. For example, in the early 1960’s, a drug known as thalidomide was used to treat morning sickness.