<span>Discovery</span>
The operon model (Lac operon) of the regulation
of gene expression in bacteria was proposed by Jacob and Monod and hey got
noble prize in 1965 in Physiology and Medicine for this discovery.
Definition
<span> “</span><span>Operons are cluster of coregulated bacterial
genes which regulate other genes responsible for protein synthesis” </span>
Explanation
<span>Operons were first studied
in the bacterium E.coli, and they
involve the enzyme of lactose metabolism and tryptophan biosynthesis. </span>
Structure of Operon
<span> </span>Operon is generally
composed of three basic DNA components:
1. Promotor:
<span> It is a nucleotide sequence which is
recognized by RNA polymerase and initiate transcription.</span>
2. Operator:
It is a segment of DNA
that is present between the promotor and other genes to be transcribed. In presence
of repressor, RNA polymerase is physically obstructed and cannot transcribe the
genes. In the absence of repressor, operator is active and start transcription
of other proteins.
3. Structural genes:
<span>These genes are
responsible for synthesis of targeted proteins under the influence of operator<span>. </span></span>
Example of operon model:
<span> In bacteria two operon model have been
extensively studied, these are:</span>
<span> a. Lac Operon, and</span>
<span> b. Tryptophan operon</span>
The nurse instructs the client to take the medication: Within
2 hours after a full meal. The nurse
tells the client need Liver function studies laboratory test will need to be monitored while taking this
medication. <span>The nurse is advising a client with acquired
immunodeficiency syndrome (AIDS) to avoid the consumption of undercooked meat.
Which infection can be prevented in the client by Toxoplasmosis encephalitis. </span>
The body wall<span> of a star fish is made up of a thin cuticle, an epidermis with a single layer of cells, a thick dermis composed of connective tissue and a thin coelomic myoepithelial layer, which allows the longitudinal and circular musculature.</span>
Answer:
The chance that their <u>child will not be able to roll his tongue will be zero</u>.
The chances to have a child with tongue rolling ability is 100%.
Explanation:
In complete dominance, a dominant gene completely manifests over a recessive gene. If tongue rolling is a dominant trait, this means that the gene that expresses this trait is dominant over the recessive one that does not allow the person to roll the tongue.
If the gene for tongue rolling is called T, then a person that is homozygous dominant for this trait will have the following genotype: TT. If the person is heterozygous for this trait, the genotype will be Tt. And if a person is homozygous recessive for the trait, this person´s genotype will be tt.
When two homozygous dominant individuals mate, their chances to have a child with tongue rolling ability is 100%.
This is:
Parental) TT x TT
Gametes) T T T T
Punnet Square) T T
T TT TT
T TT TT
F1) Genotype: 100% TT, or 4/4 TT
Phenotype: 100% Tongue rolling capable.
They can cause changes in a certain cell that can cause the growth or death in a cell.
