Lipids are a class of organic compounds, which suits best under the column macromolecules on the hierarchy of biological organization.
Biological organization refers to the hierarchy of composite biological systems and compositions, which illustrate life using a reductionistic method. The conventional hierarchy moves from an atom to more complex biospheres.
Each of the level in the hierarchy signifies an enhancement in the organizational complexity, with each component being mainly comprised of the previous basic unit level.
The Correct answer would be e. Mutate; are selected; evolve
That would be the Endocrine system which secretes hormones into the blood through glands
The sun does however, revolve about a point in the centre of our galaxy. Taking entire solar system with it at a speed of 220 km/s. This period of orbit takes 225 million years. The sun revolves at about once every 25days at its equator and up to 30 days near its poles.