Answer:
b. flat rotation curves in spiral galaxies
Explanation:
Dark matter accounts for majority of the matter in the universe (about 85%). It is considered to be composed of subatomic particles which are yet to be discovered. Dark matter cannot be observed because it does not emit light that can be detected. Only its gravitational effect is visible.
Astronomers when calculated the mass of the visible matter and tried to account for the observed speed of stars in the galaxy, there was a mismatch. To understand what caused this mismatch, astronomers gave name to the invisible matter as the Dark Matter.
The expected velocity of stars should decrease away from the near the center of the galaxy but a constant velocity of stars was observed that is a relatively flat rotation curve was obtained.
Thus, flat rotation curves in spiral galaxies in an evidence of Dark Matter.
Answer:
This is an example of Morphological and structural adaptation
Explanation:
The morphological and structural adaptation is an anatomical adaptation, where living beings exhibit some characteristics that allow them to survive according to the environment in which they are, either promoting a camouflage, or resembling animals that are dangerous to frighten possible predators.
An example of this can be seen in the question above, where the hare, in order to survive and reproduce, allow the hair to become white as snow, and can camouflage themselves in the environment in which they are.
Answer:
The sedimentary rock is a rock that has been made from other rocks that had existed in the Earth. The sedimentary rock has different layers of rock that can take form as gravel, stone, and maybe even a few gems inside.
Explanation:
The first step would be that the rock would be in liquid form, 2nd stage would be the sludge stage, which would contain both solids and liquids, then overtime, the sedimentary rock would form. The Sedimentary rock can also be made out of mud and sand that has been under countless pressure overtime. But you would be most able to find one near deserts, lakes, seas, and rivers. So bodies of water would give you the advantage to find this rock.
