Monthly Archives: October 2009
Need Help For Biology Ap Test!!!!?
i am reviewing bio for the ap test on monday..i need help with ANIMALS….
our teacher told us to make a chart on how the following systems work in each phylum…
Systems :
MUSCULAR
REPRODUCTIVE
ENDOCRINE
IMMUNE
how the above systems work in all the phylums including porifera, Cnidaria, plathyelminthes…… all the way to chordates!! need urgent helppppppppppppp
What Kind Of A Respiratory System Did Prehistoric Insects Have?
I was just wondering…
insects have spiracles that connect directly to their organs and this is useful because they are so small. However…. we are taught by archaeologists that millions of years ago, insects were far bigger in terms of biomass than they are today. Spiracles would probably not be efficient for organisms this size, so what kind of a respiratory system did these insects have?