Answer;
Gold
Gold is a non renewable resource.
Explanation;
Non renewable resources are those resources of economic value that can not be readily replaced by natural means on a level that is equivalent to its consumption.
Examples of non renewable resources include; fossil fuels such as oil, natural gas and coal; because their source is not sustainable.
Neutrons
The atomic mass is the weight of the protons and neutrons in the nucleus.
The mechanisms of reproductive isolation prevent the reproduction of two individuals from different species. The prezygotic mechanisms disrupt the stages of reproduction before the forming of the zygote or prevent the mating at the start, and the postzygotic mechanisms affect the stages of reproduction after the forming of the zygote.
So, the first and the third example (the urchins and the grasshoppers) show the prezygotic mechanism, as the two individuals are not able to mate or form a zygote.
The second and the fourth example ( zonkey and the death of a zygote) show the working of the postzygotic mechanisms, as the zygote is formed, but it seems to be inviable, and the zonkeys are sterile, preventing the individual to reproduce.
Answer:
Proteins range in molecular weight from 1000 to more than 1 million daltons (Da), but the folded size of a globular protein is not necessary correlated to its molecular weight. Proteins composed of about 250 amino acids or less often have a simple, compact globular shape. Larger globular proteins are usually made up of two or more recognizable and distinct structures, termed domains or modules. These are compact, folded protein structures that are usually stable by themselves in aqueous solution. Typical domain structures consist of hydrophobic cores with hydrophilic surfaces. Individual domains often possess unique functional behaviors and often perform unique functions within the larger protein in which they are found.
