. Your guide wamed you about star activity characteristic of particular RE & DNA
methylation that you are going to deal with it. What do you understand by it?
10 marks question so give ans properly
and irrelevant answer will be reported
Answers
Answer:
Endoplasmic reticulum transpires in two forms: a type with ribosome-studded surface and another with a smooth surface. The latter is called the smooth endoplasmic reticulum, and the former is called the rough endoplasmic reticulum. These membranes form continuous folds, eventually joining the outer layer of the nuclear membrane. Except for sperm cells and red blood cells, the endoplasmic reticulum is observed in every other type of eukaryotic cell.
Endoplasmic Reticulum Diagram
The below diagram shows the variants of endoplasmic reticulum:
Rough ER
Smooth ER
Rough endoplasmic reticulum has ribosomes
embedded within its structure, giving a “rough” appearance. Smooth endoplasmic reticulum does not have these ribosomes, hence appear “smooth.”
Endoplasmic Reticulum Diagram
Endoplasmic Reticulum diagram
Structure of Endoplasmic Reticulum
DNA is a group of molecules that is responsible for carrying and transmitting the hereditary materials or the genetic instructions from parents to offsprings.”
DNA is known as Deoxyribonucleic Acid. It is an organic compound that has a unique molecular structure. It is found in all prokaryotic cells and eukaryotic cells.
Answer:
In the mammalian genome, DNA methylation is an epigenetic mechanism involving the transfer of a methyl group onto the C5 position of the cytosine to form 5-methylcytosine. DNA methylation regulates gene expression by recruiting proteins involved in gene repression or by inhibiting the binding of transcription factor(s) to DNA. During development, the pattern of DNA methylation in the genome changes as a result of a dynamic process involving both de novo DNA methylation and demethylation. As a consequence, differentiated cells develop a stable and unique DNA methylation pattern that regulates tissue-specific gene transcription. In this chapter, we will review the process of DNA methylation and demethylation in the nervous system. We will describe the DNA (de)methylation machinery and its association with other epigenetic mechanisms such as histone modifications and noncoding RNAs. Intriguingly, postmitotic neurons still express DNA methyltransferases and components involved in DNA demethylation. Moreover, neuronal activity can modulate their pattern of DNA methylation in response to physiological and environmental stimuli.