An e-reader, also called an e-book reader or e-book device, is a mobile electronic device that is designed primarily for the purpose of reading e-books and digital periodicals. An e-reader is similar in form, but more limited in purpose than a tablet.-book reading is increasing in the US; by 2014 28% of adults had read an e-book, compared to 23% in 2013.
1 Developmental biology â The study of the processes by which an organism changes from a single cell into a mature, multicellular individual.  Epigenetics (pronunciation) â The study of heritable changes in phenotype caused by mechanisms other than the alteration of nucleotide sequences.
In the categorization used by the Humanities Indicators, the natural sciences consist of the following subfields: 1  Physical sciences (astronomy, chemistry, geology, physics, etc.);  Life sciences (zoology, botany, molecular bioscience, etc.--excludes agricultural science);