Answer:
c. individuals of a single species that live and interact in one area
Explanation:
When some organisms belonging to a single species live together in an area, they make a population. Since members of a population belong to the same species, they are able to interbreed among themselves to produce viable and fertile progeny. They have the same resource requirement and interact with each other. All the plants of <em>Mangifera indica</em> present in an area make a population. Likewise, a group of <em>Panthera tigris</em> living in a forest together makes the tiger population of that area.
DNA is considered the molecule of life because it contains the instructions that ensure the continuity of life. Employment of DNA to code for protein is the basis of all life on earth.
In all living things, inherited DNA is used to code for amino acids which when joined or linked together in a deliberate specific manner form polypeptides which make up proteins. These proteins are responsible for structure and function of cells.
For example DNA provides information to make four polypeptide (two beta and two alpha ) chains which make up hemoglobin, the protein that functions as the oxygen carrier in red blood cells. In summary,
DNA → protein → trait, and that relationship is the physical basis of life.
Stars are classified based on the spectral type (i.e. a means to measure the photospheric temperature and density by getting information about the ionisation state).
Under the Morgan–Keenan (MK) system using the letters O, B, A, F, G, K, and M, a sequence from the hottest (O type) to the coolest (M type) (Harvard Spectral classification based on the surface temperature of the stars). A luminosity class is added to the spectral class using Roman numerals (Yerkes Spectral classification). This is based on the width of certain absorption lines in the star's spectrum (0 or Ia+ - hypergiants, I - supergiants, II - bright giants, III - regular giants, IV - sub-giants, V - main-sequence stars, sd - sub-dwarfs, and D - white dwarfs).