<u>Answer:
</u>
When the outer electron shell is full in an element, this creates a Noble gas.
<u>Explanation</u>:
Noble gases are the elements that belong to group 18 in the periodic table. Noble gases are also called as inert gases. The outermost shell of the noble gases are fully filled by electrons. Due to this the noble gases don’t react with any other elements and remain isolated.
There are 6 noble gases in the periodic table. They are helium (He), Argon (Ar), Neon (Ne) Krypton (Kr), Radon (Rn) and Xenon (Xe). Noble gases conduct electricity. They are fluorescent, odorless and colorless. Noble gases are used a maintain stable elements in a constant and safe environment.
Answer:
D.) repressor DNA-binding site mutation
Explanation:
lacl prevents the repressor polypeptide is a mutant that prevent operon from binding lactose, and thus will bind to the operator and be non-inducible.. This mutant will represses the lac operon whether lactose is present or not and the lac operon will not be expressed. It is also called“super-supperesor".
The lacI locus – One type of mutant allele of lacI (callled I-) prevents the production of a repressor polypeptide or produces a polypeptide that will not allow to bind to the operator sequence.
This is also a constitutive expresser of the lac operon because absence of repressor binding permits transcription.
Answer:
Explanation:
In an atom, there is a dense center known as the nucleus. It is made up of two subatomic particles: <u>protons</u> and <u>neutrons</u>. The protons have a positive charge and the neutrons have no charge, so overall the nucleus is positively charged.
The third subatomic particles, negatively charged electrons, are located around the nucleus in a cloud.
The particles in the nucleus are 
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