Acondition that causes narrowing of the coronary arteries so blood flow to the heart muscle is reduced
a. arteries
b. atriums
c. capillaries
d. carotid arteries

Environmental differences within ecosystems are generally caused by

Which of the following statements about brain development and early childhood is true? the brain of a 5 year old is 60 percent the size of an adult brain the overall size of the brain does not increase dramatically from ages 3-15 by the time a child is 3 years of age, the brain is 25 percent of it's adult size the development that occurs inside the brain ends at the onset of adolescence

List the four types of organic compounds found in all living things and explain why they are important.