Dorsal-ventral patterning within the ectoderm of the Drosophila embryo requires seven zygotic genes including sog (short gastrulation). Sog is expressed in the ventrolateral region of the embryo that gives rise to the nerve cord.
Biology explores the interconnectedness of all living things and the environment. Through learning in biology, students discover that life involves interactions at all levels of organisation: cells interact with their environment and with each other, so do organs, organisms and ecosystems.
Physiology is the branch of biology that deals with the functions of living organisms and the parts of which they are made. This scientific discipline covers a wide variety of functions, ranging from the cellular and below to the interaction of organ systems that keep the most complex biological machines running.