Gene regulation is
the process of controlling which genes in a cell’s DNA are expressed
(used to make a functional product such as a protein). Different cells in a multicellular organism may express very different sets of genes, even though they contain the same DNA.
What is regulation of gene expression Class 12?
Regulation of gene expression refers to
the control of the amount and timing of the appearance of the functional product of a gene
. According to Central Dogma, DNA can undergo replication to form DNA and transcription to form RNA. RNA can undergo replication to form RNA and translation to form a protein.
What is a means of regulating gene expression?
Gene regulation is
the process of turning genes on and off
. … Gene regulation can also help an organism respond to its environment. Gene regulation is accomplished by a variety of mechanisms including chemically modifying genes and using regulatory proteins to turn genes on or off.
What is gene expression in simple terms?
Gene Expression
= Gene expression is
the process by which the information encoded in a gene is used to direct the assembly of a protein molecule
. The cell reads the sequence of the gene in groups of three bases. Each group of three bases (codon) corresponds to one of 20 different amino acids used to build the protein.
What is the importance of gene regulation?
Gene regulation is an
important part of normal development
. Genes are turned on and off in different patterns during development to make a brain cell look and act different from a liver cell or a muscle cell, for example. Gene regulation also allows cells to react quickly to changes in their environments.
What are the steps of gene expression?
It consists of two major steps:
transcription and translation
. Together, transcription and translation are known as gene expression. During the process of transcription, the information stored in a gene’s DNA is passed to a similar molecule called RNA (ribonucleic acid) in the cell nucleus.
What is an example of gene regulation?
Gene regulation makes cells different
For example, one of the jobs of the liver is
to remove toxic substances like alcohol from the bloodstream
. To do this, liver cells express genes encoding subunits (pieces) of an enzyme called alcohol dehydrogenase. This enzyme breaks alcohol down into a non-toxic molecule.
What is gene and its structure?
Gene structure is
the organisation of specialised sequence elements within a gene
. Genes contain the information necessary for living cells to survive and reproduce. In most organisms, genes are made of DNA, where the particular DNA sequence determines the function of the gene.
Which is the largest human gene?
The largest known gene is
the human dystrophin gene
, which has 79 exons spanning at least 2,300 kilobases (kb).
What is in a gene?
A gene is the basic physical and functional unit of heredity. Genes are
made up of DNA
. Some genes act as instructions to make molecules called proteins. However, many genes do not code for proteins.
What causes gene expression?
Gene expression is influenced by numerous factors, including molecules within the cell,
mutations causing dominant negative effects
and haploinsufficiency, signaling molecules from surrounding cells and the environment, and epistasis. Various molecules within the cell modulate gene expression.
What is the first stage of gene expression?
Transcription
is the first step of gene expression. During this process, the DNA sequence of a gene is copied into RNA. Before transcription can take place, the DNA double helix must unwind near the gene that is getting transcribed. The region of opened-up DNA is called a transcription bubble.
Where Does gene expression occur?
Prokaryotic gene expression (both transcription and translation) occurs
within the cytoplasm of a cell
due to the lack of a defined nucleus; thus, the DNA is freely located within the cytoplasm. Eukaryotic gene expression occurs in both the nucleus (transcription) and cytoplasm (translation).
Why is transcriptional regulation important?
In molecular biology and genetics, transcriptional regulation is the means by which
a cell regulates the conversion of DNA to RNA (transcription)
, thereby orchestrating gene activity. … This control allows the cell or organism to respond to a variety of intra- and extracellular signals and thus mount a response.
How do bacteria control gene expression?
Bacteria have specific regulatory molecules that control whether a particular gene will be
transcribed into mRNA
. Often, these molecules act by binding to DNA near the gene and helping or blocking the transcription enzyme, RNA polymerase.
What are the three steps of gene expression?
Transcription takes place in three steps:
initiation, elongation, and termination
. The steps are illustrated in Figure 2. Figure 2. Transcription occurs in the three steps—initiation, elongation, and termination—all shown here.
