Fill in the Blanks


1		are rod-shaped structures that contain all basic hereditary information.


2		Scientists mapped the specific location and sequence of every human gene as part of the massive .


3		In , health care providers inject genes to correct particular diseases directly into a patient's bloodstream.


4		When an egg becomes fertilized by the sperm, the resulting one-celled entity is called a(n) .


5		The is the point at which the fetus can survive if born prematurely, at about prenatal age 22 weeks.


6		Before birth, a fetus passes through several which is the time when organisms are particularly susceptible to certain kinds of stimuli.


7		Some of the more profound consequences in fetal development are brought about by , environmental agents such as a drug, chemical, virus, or other factor that produces a birth defect.


8		is a procedure in which a woman's eggs are removed from her ovaries, and a man's sperm is used to fertilize the eggs in a laboratory. A fertilized egg is then implanted in a woman's uterus.