Answer:Valves stop blood flowing backwards
Explanation: Valve are flags of tissue that control the direction of the blood in our heart.,it prevent the backwards flow of blood. valves regulate blood from flowing back into the atria.The right and left atrio-ventricular valves prevent blood from flowing backwards into atria. When the ventricle is full,the valve prevent backwards flow of blood.
 
        
             
        
        
        
False, because nucleotides are what make up a persons DNA so each person has its own unique order.
        
             
        
        
        
Answer:
In biology, a gene is a basic unit of heredity and a sequence of nucleotides in DNA or RNA that encodes the synthesis of a gene product, either RNA or protein. During gene expression, the DNA is first copied into RNA. 
Euchromatin is a lightly packed form of chromatin that is enriched in genes, and is often under active transcription. Euchromatin comprises the most active portion of the genome within the cell nucleus. 92% of the human genome is euchromatic. 
The genes present in heterochromatin are usually inactive. The genes present in euchromatin are either already active or will be active during growth. Heterochromatin is transcriptionally-inactive. Euchromatin is transcriptionally. (This one here is the difference) 
 
        
             
        
        
        
Answer:
It is similar because the nuclear envelope is a membrane similar to the cell membrane around the whole cell. There are pores and spaces for RNA and proteins to pass through while the nuclear envelope keeps all of the chromatin and nucleolus inside. When the cell is in a resting state there is something called chromatin in the nucleus.
Explanation:
 
        
                    
             
        
        
        
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