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 summary, there are eight major branches of biology: 1  Biochemists study the chemistry of living things, like proteins. 2  Molecular biology is the study of genetics and DNA. 3  Cell biology studies the cells that contain DNA, like cancer or brain cells.