Hope this helps! This is what I found when googling it!
 
        
        
        
Answer: Phenotype
Explanation:
The phenotype is the set of physical characteristics of an individual, that make it different from other individuals and are evident to the eye.
While the genes inherited from the parents determine the genotype of the individual, that's not enough to fully determine how it will look when it develops, as the ambient where it will grow takes a great part of it. Those factors are called epigenetics.
How an individual will look, its phenotype, is a result of its genes and the epigenetic factors.
 
        
             
        
        
        
An operon is a stretch of DNA consisting of an operator, a promoter, and genes for a related set of proteins, usually making up an entire metabolic pathway.
operon is a functional unit of gene.
This cluster of gene transcribed together to give a messenger RNA which further give rises to protein.
operator in operon is the site where repressor binds.
promoter is where Mrna binds , where our genes are transcribed
structural genes, they code for the enzyme that are involved in this metabolic pathway.
Operons have an important role to play as they produce protein for the cell this serves them energy, the protein is produced only when energy is required.
To know more about operon,
brainly.com/question/14331566
#SPJ4
 
        
             
        
        
        
The best and most correct answer among the choices provided by your question is the first choice or letter A. <span>A biological agent that cannot reproduce on its own is a VIRUS.
</span>A virus<span> is a small infectious agent that replicates only inside the living cells of other organisms.
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I hope my answer has come to your help. Thank you for posting your question here in Brainly.
        
                    
             
        
        
        
In biochemistry, aligand is a substance that forms a complex with a biomolecule to serve abiological purpose. In protein-ligandbinding, the ligand is usually a molecule which produces a signal by binding to a site on a target protein.
Receptor mediated endocytosis is an endocytotic mechanism in which specific molecules are ingested into the cell. The specificity results from a receptor-ligand interaction. Receptors on the plasma membrane of the target tissue will specifically bind to ligands on the outside of the cell. An endocytotic process occurs and the ligand is ingested.
A very well studied example of receptor mediated endocytosis involves the metabolism of cholesterol.