Final answer:
Epithelial cells in an animal with 28 chromosomes in its nerve cells will also have 28 chromosomes. This consistency is due to all somatic cells containing the same number of chromosomes, which is maintained during cellular differentiation.
Step-by-step explanation:
If a nerve cell of a particular animal has 28 chromosomes, epithelial cells of the same animal will also have 28 chromosomes.
In multicellular organisms, somatic cells (which include nerve cells and epithelial cells) are generally diploid, meaning they contain two sets of chromosomes, one set inherited from each parent. The total number of chromosomes is consistent throughout the various somatic cell types within an individual organism. This is a result of the cellular differentiation process where unspecialized cells become specialized, while the genetic material—chromosomes—remains the same. This fact has been confirmed since the discovery of cell division processes mitosis and meiosis, and further reinforced by experiments such as those by John Gurdon and Shinya Yamanaka on cellular genome integrity.
In contrast, gametes (sperm and egg cells), which are created through meiosis, have half the number of chromosomes compared to somatic cells. Thus, in an animal where a muscle cell (another type of somatic cell) has 32 chromosomes, the gametes would have 16 chromosomes.