National Dental Assisting Examining Board (NDAEB) Practice Exam

Which of the following is known as a teratogen that can contribute to congenital malformation?

1. Dietary Supplements

2. Microorganisms

3. Radiation

4. Genetic Mutations

The correct answer is: Radiation

Radiation is recognized as a teratogen because it has the potential to cause congenital malformations in a developing fetus. Teratogens are agents or factors that can cause malformation in an embryo or fetus during pregnancy, particularly during critical periods of development. Exposure to high levels of ionizing radiation, especially in the early stages of pregnancy, can disrupt normal cellular processes, leading to developmental anomalies and physical defects. In contrast, while dietary supplements can affect fetal development if taken excessively or improperly, they're not inherently classified as teratogens. Microorganisms, such as certain infections during pregnancy, can also lead to birth defects. However, they act as teratogenic agents through a different mechanism than radiation. Genetic mutations play a critical role in hereditary diseases and can indeed affect development, but they do not fall under the classification of teratogens in the same context as environmental factors like radiation, which directly influence fetal development during in utero exposure.