What role do plants play in an ecosystem? a. they convert sunlight into usable energy. b. they release oxygen that organisms use to breathe. c. they cause the high and low tides of the sea. d. they’re used in making synthetic cloth fibers.

Agroup of 50 adult male humans were in a clinical study to determine how much niacin is toxic. during the first two weeks of the study, members of the group consumed only a formula diet that was nutritionally complete, except it contained 24 mg niacin, which is 1.5 times the rda for niacin (males). at that point in the study, all members reported feeling fine. during the next week, they were given a formula that contained 48 mg niacin. within a few days of consuming this formula, 90% of the participants reported feeling ill, and they complained of having upset stomachs and reddened facial skin. at that point, researchers gave the subjects a formula that contain 16 mg niacin. after a week of consuming the new formula, all participants reported feeling well again. based on this information, the researchers concluded that the amdr for niacin is between 16 and 24 mg/day. ul for niacin was between 24 and 48 mg/day. human requirement for niacin is 16 mg/day. eer for niacin was 16 mg/day.

What is the term for bone marrow tumor? osteoma myeloma osteocele osteomyoma

Which of these is the muscular tube that leads from the mouth to the stomach? a.epiglottisb.uvulac.soft palated.esophagus