Fish respiratory systems exchange gas and receive oxygen at the gills. this oxygen then enters the blood stream and is pumped through the heart and back through the gills without first returning to the heart. this order of events best describes which type of circulation system?
a) double loop
b) single loop
c) open
d) recycling

Before the can be observed by using a transmission electron microscope, cells are sliced into very thin sections. what disadvantage does this procedure present in the study of cellular parts

What is the function of the somatic nervous system? connects the brain and the spinal cord to the rest of the body carry signals to the muscles and glands includes all nerves controlling the muscular system and external sensory receptors controls internal organs like the heart and bladder

How are the reproductive cycles of a fungus and a pteridophyte similar? a)both organisms form fruiting bodies that produce diploid seeds. b)both organisms produce haploid spores and exhibit diploid and haploid stages. c)both organisms reproduce sexually when two haploid hyphae fuse. d)both organisms exhibit a diploid stage and are only able to reproduce asexually.