Some complex multicellular organisms are organized at four levels to increase efficiency. what is the correct order of organization, from the simplest to the most complex?

a.
organ, tissue, cell, organ system

b.
cell, organ, organ system, tissue

c.
tissue, cell, organ system, organ

d.
cell, tissue, organ, organ system

The eruption of a nearby volcano causes a prairie ecosystem to receive a lot less sunlight. which of these is most likely effect on the ecosystem?

What are antigens and antibodies? how are they involved in the body’s response to incompatible blood?

Which of these statements is true about autotrophs, but not heterotrophs? a. they use sugar and oxygen to make carbon dioxide and water. b. they use chlorophyll and oxygen to make carbon dioxide and water. c. they use sunlight, water, and carbon dioxide to make sugars. d. they use sunlight, water, and oxygen to make chlorophyll.