Answer:
the ductus arteriosus is a normal blood vessel that connects two major arteries — the aorta and the pulmonary artery — that carry blood away from the heart. The lungs are not used while a fetus is in the womb because the baby gets oxygen directly from the mother's placenta.planation:
Answer:
DNA is known as the genetic material of all the organisms except some viruses. DNA is made of four nitrogenous bases, pentose sugar and the phosphate group.
1. Watson and crick meant that DNA shows the complementary base pairing in which adenine binds with thymine and cytosine binds with guanine. This base pairing has allowed the single DNA stranded to carry the information that are necessary for the synthesis of the complementary daughter strand.
2.The separation of the strand should be done in such a way that friends should get each single strand of DNA. The information stored in the DNA is available in the single strand of DNA.