According to Kail and Cavanaugh "The outer layer or ectoderm becomes hair, the outer layer of skin, and the nervous system; the middle layer or mesoderm forms muscles, bones, and the circulatory system; the inner layer or endoderm forms the digestive system and the lungs (Kail & Cavanaugh, 2004)." ... At the age of viability which is between twenty-two to twenty-eight weeks, most of the fetus's body system can function sound enough to survive if it was born. ...

• Word Count: 2119
• Approx Pages: 8
• Has Bibliography
• Grade Level: High School

The thick secretions also get into the pancreas, making it difficult for digestive enzymes to reach the intestines to help break down and absorb food. ... Its hard to imagine that within 15 years all the problems we have heard about will be extinct no more schizophrenia, alcoholism, Alzheimer's, depression no more Gene mutations that cause common diseases like heart disease, diabetes, immune system disorders, and even birth defects. ...

• Word Count: 1423
• Approx Pages: 6
• Grade Level: Undergraduate

The DNA of human blood can be recovered from the digestive tract of an insect that has feed on an individual. ... The two dark spots on the left are the posterior spiracles, or openings to the breathing system. ...

• Word Count: 2073
• Approx Pages: 8
• Grade Level: High School

The DNA of human blood can be recovered from the digestive tract of an insect that has feed on an individual. ... The two dark spots on the left are the posterior spiracles, or openings to the breathing system. ...

• Word Count: 2083
• Approx Pages: 8
• Grade Level: High School