20 points :) How does the flame cell function in a planarian?
Select one:
a. Carbon dioxide is excreted by them through the mouth.
b. Cilia sweep water into excretory tubules.
c. Cilia sweep water out of the body.
d. Dissolved oxygen and nutrients are swept into the body by diffusion.

No plagiarizing ! 6th grade work! easy and 100 compare the parts of a cell and the cell as a whole to another common nonliving system (i.e., a car, a city, describe the parts of a cell and their primary function.

Select the correct answer from each drop-down menu. the lac operon in e.coli regulates genes that code for enzymes required for breakdown of lactose. the lac operon is operon that is activated in the presence of .

Even though the ostrich is a flightless bird, ostriches still possess wings that stretch approximately two meters across when fully extended. scientists speculate that when dinosaurs became extinct, some of the birds that lived during that time became land dwellers since they were able to consume the food that the dinosaurs once ate. over time, these species grew larger and heavier. eventually, the ostrich species became too big to fly. the wings found on ostriches are known as a. analogous structures. b. homologous structures. c. vestigial structures. d. symmetrical structures.