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.
<span>This condition is called Edema. It is when something swells up, which happens when too much fluid is trapped in the soft tissues. Blood vessels emit the fluid which fills up in the soft tissue. It can happen because of burns, allergic reactions, and even pregnancy. (Sometimes women's feet swell.)</span>
Answer:
This means that the two separate rocks were once part of one piece of rock. These layers got separated most probably by continental drift as a result of tectonic plate movements. An example of such a fossil is the Mesosaurus, a freshwater crocodile-like reptile, that is found in Southern Africa and Eastern South America continents- that means they were once one land mass.
The environment in these two separate layers would most likely be different. As the layers drift apart from each other , they drift across latitudes that are determinants of climate in a region. Therefore, even the organisms in these two rock layers will evolve differently (even though they will share a common ancestor) in adaptation to respective environments – this is called allopatric speciation.
