The four most common teratogens are tobacco, alcohol, medications and illegal drugs. Teratogens are substances that could harm a developing fetus by affecting growth and causing birth defects or death. More »

Jupiter, Saturn, Uranus and Neptune are all similar in size and material composition. These planets are known as gas giants, and they are made almost entirely of hydrogen and helium. They also lack a solid surface. More »

The four components that all computers have in common are input, output, storage and processing, according to Intel's educational website. Input devices accept information into a computer, while output displays the infor... More »

The most common causes of feeling lightheaded or dizziness include allergies, anxiety and stress, illnesses such as cold or flu, fever, vomiting, diarrhea, dehydration, hyperventilation and the use of alcohol, illegal dr... More » Health Pain & Symptoms

Chromosomal abnormalities, alcohol use during pregnancy and environmental factors are all potential causes of birth defects. A birth defect is a problem with the formation of body parts, how the body parts work or how th... More » Health Women's Health Pregnancy

Staying at a healthy weight, avoiding excessive alcohol and caffeine intake, and having sex daily or every other day may increase a woman's chance of conceiving, according to WebMD. Tracking menstrual cycles and ovulatio... More » Health Women's Health Pregnancy

According to the American Pregnancy Association, alcohol negatively affects the fetus during pregnancy by increasing the risk for Fetal Alcohol Spectrum Disorders. Alcohol is a teratogen; it is harmful to human developme... More »