<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>
In a clinical situation where it is essential to control microbial growth that includes both mycobacteria and endospores, the chemical <span>agent that would be the most effective to guarantee the broadest disinfection are chlorines.
Chlorine (Cl) is a yellow-green gas often used for disinfection in its liquid form. </span>
Answer: consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder).
The cost-benefit analysis done to investigate a proposed mine site would take into consideration the cost of environmental restoration after mining and the value of the ore to be extracted from the mine.
<h3>Cost-benefit analysis</h3>
This is an analysis done to assess the cost and benefits of actions.
For an action to be profitable, the benefits must be more than the cost.
In this case, for a mine site, the value of the ore to be extracted from the mine has to be more than the cost of having to restore the site after mining.
Every other cost can also come in but the two major ones are those highlighted.
More on cost-benefit analysis can be found here: brainly.com/question/3443140
Answer:
Most biomolecules are organic compounds, and just four elements, oxygen, carbon, hydrogen, and nitrogen make up 96% of the human body's mass. But many other elements, such as the various biometals, are also present in small amounts.
