31 March 2015, 04:24 PM ET
Pregnancy lasts about 40 weeks and is divided into three stages, or trimesters, each with unique symptoms and changes in the mother's body and in fetal development.
30 March 2015, 07:49 PM ET
Science is a systematic and logical approach to discovering how things in the universe work.
26 March 2015, 12:25 PM ET
The human brain is the command center for the human nervous system.
26 March 2015, 02:52 AM ET
Infrared radiation is a type of electromagnetic radiation. It is invisible to human eyes, but people can feel it as heat.
26 March 2015, 02:43 AM ET
Microwaves are a type of electromagnetic radiation, and are useful in communications, radar and cooking.
26 March 2015, 02:32 AM ET
Algebra is a branch of mathematics dealing with symbols and the rules for manipulating those symbols.
25 March 2015, 11:56 PM ET
In science, a law describes an observed phenomenon.
24 March 2015, 08:28 PM ET
Empirical evidence is information that is acquired by observation or experimentation.
23 March 2015, 10:23 PM ET
Deduction starts out with a generalization that follows a process to reach a specific, logical conclusion. Induction is the opposite - making a generalization from a set of specific observations.
23 March 2015, 10:21 PM ET
Giganotosaurus was one of the largest meat-eating dinosaurs.
20 March 2015, 11:35 PM ET
Gamma-rays are a form of electromagnetic radiation. They can be used to treat cancer, and gamma-ray bursts are studied by astronomers.
20 March 2015, 08:50 PM ET
A woman can deliver her baby either by vaginal birth or a C-section. Both delivery methods have advantages and disadvantages.
19 March 2015, 10:51 PM ET
A Cesarean section is a type of surgery used to deliver a baby through an incision in the mother's abdomen.
19 March 2015, 10:41 PM ET
Diplodocus was a long-necked, long-tailed dinosaur that roamed western North America.
17 March 2015, 10:14 PM ET
A scientific theory is based on careful examination of facts. It is much different from the non-scientific use of the word.
17 March 2015, 10:03 PM ET
A hypothesis is the first step in the scientific method. It begins by asking, 'What if …?'
16 March 2015, 09:56 PM ET
Every year, tens of thousands of Americans die from suicide. It is the third leading cause of death among young people between the ages of 10 and 24, amounting to about 4,600 deaths a year.
13 March 2015, 06:21 PM ET
Breast cancer is an uncontrolled growth of cells that starts in the breast tissue. About one in eight women in the United States will develop the condition in her lifetime.
12 March 2015, 10:19 PM ET
X-rays are a form of electromagnetic radiation. One of the most common uses of X-rays is for medical imaging. X-rays are also used in treating cancer and in exploring the cosmos.
12 March 2015, 10:11 PM ET
Electromagnetic radiation is a form of energy that includes radio waves, microwaves, X-rays and gamma rays, as well as visible light.
12 March 2015, 10:03 PM ET
Amazing views from 1947 to 2012, including several firsts.
10 March 2015, 10:24 PM ET
Heroin is an opiate drug and a high potential for abuse.
10 March 2015, 10:16 PM ET
The San Andreas Fault in California is a strike-slip fault that marks the boundary between two of Earth's tectonic plates.
10 March 2015, 10:05 PM ET
The different ways that the environment gets contaminated.
09 March 2015, 10:07 PM ET
Chronic kidney disease (CKD) is the gradual and permanent loss of kidney function over time, usually over months to years.
09 March 2015, 10:02 PM ET
Qigong is an exercise and healing technique developed in China more than 4,000 years ago.
06 March 2015, 04:48 PM ET
HDL is “good” cholesterol; LDL is “bad” cholesterol. HDL helps lower LDL. Too much LDL can lead to heart disease and heart attacks.
05 March 2015, 11:54 PM ET
Treatment with acupuncture needles does work to alleviate pain and nausea, studies show.
05 March 2015, 11:31 PM ET
Gallstones are small deposits of bile inside the gallbladder, a saclike structure that stores the bile for digestion in the small intestine.
05 March 2015, 11:05 PM ET
Each year, rip currents kill more people than sharks or jellyfish or even hurricanes.
04 March 2015, 11:41 PM ET
CRE are a type of bacteria that have become resistant to most antibiotics. Infections usually occur in health care settings.
04 March 2015, 10:02 PM ET
Deforestation, the permanent destruction of forests in order to make the land available for other uses, is considered to be a contributing factor to global climate change.