Answer:
the heart it is because the heart beats and it goes up and down
 
        
             
        
        
        
Answer:
The main job of red blood cells, or erythrocytes, is to carry oxygen from the lungs to the body tissues and carbon dioxide as a waste product, away from the tissues and back to the lungs. Hemoglobin (Hgb) is an important protein in the red blood cells that carries oxygen from the lungs to all parts of our body.
Explanation:
<em>I think it is right...</em>
<em>Please make me brainliest</em>
 
        
             
        
        
        
The hemoglobin holoenzyme (active enzyme) is a complex of an iron ion and 4 subunits- 2 hemoglobin alpha and two hemoglobin beta. People with sickle cell disease have mutated beta hemoglobins. The mutation is a single nucleotide exchange, that changes the 6th amino acid of  protein primary struture - a Glutamic acid into Valine. This one alteration changes the tree dimentional structure of hemoglobin beta so, that it forms lond fibres that disrupt the normal circular form of the red blood cells.
        
             
        
        
        
Answer:
Crossing over
Explanation:
Crossing over is the process during which two chromatids of two homologous chromosomes exchange part of their genetic segments. It occurs during the pachytene stage of prophase I of meiosis I. 
Linked genes are mostly inherited together and do not exhibit independent assortment. However, when linked genes are present far apart from each other on the same chromosome, crossing over can occur between them to produce recombinant chromatids. Therefore, crossing over can break the linkage and produce recombinant progeny as it occurs during the independent assortment of unlinked genes. 
 
        
             
        
        
        
<span>The MOSQUITO spreads more parasitic diseases to humans than any other vector.
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