Humans lived with domesticated dogs over thousands of years which resulted in many breeds of dogs. Humans bred some dogs to have thick coats to keep the dogs warm in cold climates while other dogs have thin coats that live in warm climates.
Which evidence supports the claim that dogs inherit these characteristics?
O
A. During mitosis, mutations occurred and the offspring's DNA stored this information
B. As dogs digested food, mutations occurred which changed the dog's physical appearance.
O C. Since dogs lived closely in contact with humans, the dog's genetic information remained the same.
D. During meiosis, new combinations of genetic information occurred, and the offspring's genes expressed this information.

Did humans tame woolly mammoths or other megafauna?

Considering that some people are gifted with handling animals (e.g. horse whisperers), could paleoindians or other Pleistocene peoples have gained the confidence of woolly mammoths or mastodons to use them as transportation and other tasks, the way that Asian elephants are used today?

Fewer resources would be necessary for a human to travel long distances by riding on the back of a woolly mammoth or paleocamel, as the megafauna could graze and get energy. People may also have traveled by boat during late Pleistocene times (the kelp highway along PNW).

How could we test such a hypothesis? Cave art showing a rider on the back of one of the megafauna? A bridle and/or bit? A talisman worn by a camel is known to have been crafted from a meteorite(1), and so talismans or decorations might have adorned the hypothesized woolly steed. Metal was not a known technology during stone tool usage, as far as we know, though.

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.