The role of the excretory system is to rid the body of toxic waste products. which of the following body systems also plays a direct role in removing waste products from the body?
a) endocrine
b) nervous
c) respiratory
d) skeletal

Rachel ate a piece of fruit and happened to drop the seeds in her backyard. after a few weeks, she saw a small plant with flowers growing in the backyard. which group does this plant belong to? a. angiosperms b. gymnosperms c. pteridophytes d. bryophytes e. chytrids

Photosynthesis uses co2 and cellular respiration produces co2. we call the point when the two processes are in balance--when there is no net production of co2--the compensation point. how might you limit one of the processes in order to achieve a compensation point?

Tom wants to conduct a scientific study but he needs to finish by the end of the school year. what practical way could tom work around this limitation and be successful in his study?