Answer:
 Radioisotopes are radioactive isotopes of an element
Explanation: Radioactive isotopes are detected by: photographic film.
a cloud or bubble chamber.
a liquid scintillation detector.
a Geiger-Muller counter.
 
        
                    
             
        
        
        
Answer:
The given blank can be filled with operator. 
Explanation:
The proteins that assist in turning on or turning off the function of a specific gene by getting combined with certain sections of the DNA are known as transcription factors. The transcription factors that activate the transcription of a specific gene are known as activators, while that prevents transcription and is termed as repressors.  
A repressor can be an RNA or a DNA binding protein, which prevents the articulation of genes by getting combined with the operator. A repressor, which binds with DNA prevents RNA polymerase from getting combined with the promoter, which further inhibits the transcription of the genes into mRNA.  
 
        
             
        
        
        
Answer:
I believe it's A and B
Explanation:
Hope my answer has helped you!
 
        
             
        
        
        
<span>Flatworms use a system of canals and tubes with the mouth as their excretory organ. They belong to the Phylum Platyheminthes. </span><span>Flatworms
can be cut in half creating two individuals by binary fission. Binary
fission is a type of asexual reproduction in which the offspring has the same
features and characteristics of the parent. During binary fission, the DNA
replicates into two and goes at the end of each membrane. And then the cell
membrane divides into two daughter cells. Then cytokinesis follow.</span>
        
             
        
        
        
The asnwer is Angiosperms