The Florida Keys are an archipelago (chain of islands) off the southern coast of Florida. The Keys are made of mainly softer materials like limestone and fossilized coral. The Hawaiian Islands are also an archipelago, but are made of much harder igneous rock. Which of the following explains why the Hawaiian Islands are made of such different materials than the Florida Keys? A.
Coral does not grow near the Hawaiian Islands.

B.
The Hawaiian Islands were built mostly by people.

C.
Igneous rocks are only found in the Hawaiian Islands.

D.
The Hawaiian Islands formed through volcanic eruptions.

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.