Answer:
Modern amphibians are characterized by the flexibility of their gaseous exchange mechanisms. Amphibian skin is moistened by mucous secretions and is well supplied with blood vessels. It is used for respiration to varying degrees. When lungs are present, carbon dioxide may pass out of the body across the skin, but in some salamanders there are no lungs and all respiratory exchanges occur via the skin. Even in such animals as frogs, it seems that oxygen can be taken up at times by the skin, under water for example. Therefore, regulation of respiration occurs within a single species, and the relative contribution of skin and lungs varies during the life of the animal.
Explanation:
Answer: Telomerase is the enzyme responsible for maintenance of the length of telomeres by addition of guanine-rich repetitive sequences. Telomerase activity is exhibited in gametes and stem and tumor cells.
Explanation:
Van de waals are considered the weakest bonds between any two molecules
Answer:
According to the FCC, chances are it's a scammer. It can be difficult, though, to tell if this call is fraudulent. ... If you already have an auto warranty, call your provider. The FCC urges call recipients not to respond to anyone who is pressuring them to act quickly or to pay over the phone.
