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

me

Ectocarpene is a volatile, sperm cell-attracting material released by the eggs of the seaweed ectocarpus siliculosus. its constitution is all the double bonds are cis, and the absolute configuration of the chirality center is s. draw a stereochemically accurate representation of ectocarpene.

One of the newest applications of cell technology is called cybrid embryos. this process involves replacing the nuclear material of an animal cell with human nuclear material. how might this process affect public policies about research by using stem cells? the same policies and concerns about the use of human embryonic stem cells would most likely apply. the embryos would most likely be treated like traditional animal embryos and regulated accordingly. the process of forming cybrid embryos would most likely be banned by government regulators. the embryos would be treated as regular cells because they are not fully human in origin.

What is the starting point in replication called