Answer:
last option- these waves can travel without the medium
Basically it has chemicals that break down its food and it poops the left overs out
Weathering and erosion played a big role in forming the grand canyon. The rock was being weathered, most likely mechanical weathering, and then it eroded away. Think of a pebble that is in running water. When you pick it up, it is smooth, right. But before, it was pointy. So, the grand canyon was once a big rock, and weathering broke through it making it one of the wonders of the USA.
Answer:
The bonds that are formed between nitrogenous bases are Hydrogen Bond.
Explanation:
When a hydrogen atom interract with an electronegative atom such oxygen,fluorine hydrogen bond forms,
A single hydrogen bond is weak noncovalent bond but collectively they exerts very strong interraction.
Hydrogen bonding occurs between complementary base pair .For exam An adenine base forms 2 hydrogen bonds with thymine base whereas guanine forms 3 hydrogen bonds with cytosine base.
The hydrogen bonding between complementary is very much important to stabilize the structure of DNA .