Heart disease is the leading cause of death among both men and women in the united states. it is usually caused when a sticky substance called plaque builds up in the arteries. often, the only symptoms of heart disease are chest pain or discomfort.

why do you think heart disease is so prevalent in the united states? how could heart disease affect other organ systems?

Humans are believed to have evolved in coastal regions in east africa. the region had an abundant supply of fish for early humanoids to eat. when scientists analyze the fads gene they see an interesting pattern. people whose families have lived in this area of east africa for generation show a high level of diversity in alleles for the fads gene. conversely, people whose families had migrated inland a moderate distance from sources of fish showed a much lower diversity for fads gene alleles. additionally, the fads alleles found in people whose family has lived inland for generation are almost all gene alleles which produce fads proteins with a high level of function and activity. how do anthropologists explain this?

How does photosynthesis show the conservation of mass and energy?

Which line in the graph above best illustrates an effect of the carbon dioxide level in the blood on breathing rate before, during and after a period of exercise? 1.b,2.c,3.a,4.d