Water-soluble nutrients stored in blood are routed directly from the small intestine through the portal vein to the liver before any other organ. The portal vein or hepatic portal vein is a blood vessel which carries blood from the GI tract, to the liver. The blood contains nutrients and toxins extracted from digested contents. The portal vein is not a true vein, since it conducts blood to capillary beds in the liver and not directly to the heart. It is the main component of the hepatic portal system.
The difference would be that Mercury has a denser, warmer atmosphere and Earth has a not that dense and gassy atmosphere. The Earth's atmosphere also has a lot of layers while Mercury's doesn't. Those would be the reasons for them both being different. Hope this helped!
But this rule rule is applicable only for double stranded DNA molecule. The possibility of Adenine=40% and Thymine=60% is only in single stranded DNA molecule. In the question, the DNA sample referred is a single stranded DNA. hope it helps :D