The ductus arteriosus allows fetal blood to move from the pulmonary trunk into the aorta. The ductus venosus on the other hand is a fetal vessel that transports blood from the umbilical vein to the inferior venacava. Ductus arteriosus is a blood vessel connecting the main pulmonary artery to the proximal descending aorta. It allows most of the blood from the right ventricle to bypass the fetus's fluid-filled non-functioning lungs.
Answer:
A Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene.
<span>Embryonic tissues or germ layers develop during the gastrulation stage.</span> <span>Gastrulation is a process in embryonic development during which the single-layered blastula is reorganized into a three-layered(or two-layered) structure called the gastrula. <span>Two primary germ layers(embryonic tissues) are an inner layer-endoderm and an outer layer-ectoderm. Endoderm and ectoderm interact and produce a third layer-mesoderm. Gastrulation is followed by organogenesis, three germ layers will give rise to specific tissue and organ.For example, ectoderm gives rise to epidermis and nervous system, endoderm to the digestive system and mesoderm to muscles, bones…</span></span>
The third example will be “cancer”
The main idea is that microorganisms are small and they live everywhere possible.