Question

How can the zygote produce diverse cell types found in human body? How can the cells form well-organized structures such as tissues and organs? Explain mechanisms related to these questions.

Answer 1

The answer to your query is as follows:

The process of the embryonic differentiation plays a very important role in the developmental process. It is with the help of this process that the embryonic cells get specialized and forms diverse cellular and tissue structures. Animal body is composed of different types of cells which are specialised to perform specific functions in the body.

The major key to the organisation of cells into tissues, followed by the organ, organ system and the organism identity is the embryonic differentiation of the embryo cells.

The process of the fertilisation or the fusion of the egg with the sperm leads to the formation of the zygote. The zygote triggers the embryonic differentiation through the process of cleavage and divides into multiple cells.

Blastomeres are formed in the zygotic divisions that forms a hollow sphere called as blastula. Migration of the cells occurs within the blastula at the places or the locations that will later form the detailed structure of the embryo.

In the gastrulation process, three germ layers are formed namely, the endoderm, mesoderm, and the ectoderm. The endoderm which is the innermost layer will eventually form the gut. The mesoderm which is the middle layer will develop into muscular system, the skeletal system, and the connective tissue. The ectoderm which is the outermost layer will differentiate into the nervous system and the skin.

The same types of pluripotent embryonic stem cells helps in the formation of the differentiated cell types in the embryo. A proper arrangement of the physiological mechanisms helps in some types of cells towards particular developmental pathways. Thus, helps in forming varying cell types. It is done with the help of the cell’s inherent ability to control the genes that will be expressed and will be translated into proteins.

There are a large number of diverse signals that can cause embryonic cells to choose some specific parts of the DNA. This selected part of the DNA can then be used to synthesize proteins. Thus, forming different types of the cells.

Differentiation of cells in the embryo is brought about by both internal cellular factors as well as extracellular factors that act on the cell from the outside. Much remains to be understood about the exact molecular interactions that govern cellular differentiation. It is understood, however, diversifying the ratio of and types of internal and external influences on certain cells, allows many divergent cell types to arise.

The type of the cellular development that occurs in th embryo of the humans is the regulative development. It involves the interaction of adjacent cells which is called as embryonic fields. In this type of development, the pathway of the cell can change depending on the cellular environment in which it is found.

Thus, the differences in gene expression plays a very important role in the cell’s unique morphological and physiological characteristics. The primary mechanism that decides the type of the genes that will be expressed and the other that will not is through the use of different transcription factor proteins. These will bind to the DNA and activate or stop the transcription of the different types of the genes. Thus, transcription factors helps in the specialization of the cells into hundreds of different types of the cells in the human body.

Hope it helps!