Nematodes are a model organism for many eukaryotic processes. These worms are often used in laboratory investigations regarding animal reproduction. One variety of mutant nematode cannot lay eggs in order to reproduce. However, the addition of the
neurotransmitter serotonin provides a mechanism that allows the mutant worm to lay eggs. The results of this study indicate that
multiple organ systems are involved in egg laying. Which statement best describes the interaction between organ systems in this
scenario?
es -))
A)
B)
The respiratory and the reproductive systems interact to produce eggs in
the nematode.
The respiratory and the circulatory systems interact to produce eggs in the
nematode.
The nervous and the circulatory systems interact to produce eggs in the
nematode.
The nervous and reproductive systems interact to produce eggs in the
nematode.
D)

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.    

what have scientists found to be the most efficient and effective way to insert new sequences into an individual? a-scientists have created genetically altered foods that release dna during digestion. b-scientists use viruses to insert specific gene sequences. c-scientists irradiate genes so that they can be absorbed through the skin.