Descending limb of loop of Henle
It helps to maintain the concentration of urine. It is highly permeable to water thus water is readily reabsorbed from the descending limb by osmosis. It is impermeable to sodium and chloride ions.
<h3>What is a Tubule system ?</h3>
The transverse tubular system is a network of interconnecting rings, each of which surrounds a myofibril
- The nephron uses four mechanisms to convert blood into urine: filtration, reabsorption, secretion, and excretion. These apply to numerous substances
 
- The distal convoluted tubule (DCT) and collecting duct (CD) are the final two segments of the kidney nephron. They have an important role in the absorption of many ions, and in water reabsorption.
 
Learn more about Tubule system here:
brainly.com/question/27344521
#SPJ4
 
        
             
        
        
        
The answer is "B. Marsupials". Marsupials undergo relatively premature births compared to many other species, and although this puts the baby at risk, it lessens the risks for the mother. 
        
                    
             
        
        
        
The given blank can be filled with the production of endorphins. 
The endorphins are the hormones, which are responsible for the activation of the opiate receptors in the body. They are the natural pain killers. The activation of the opiate receptors causes the analgesic effects on the body.  
These endorphins are secreted in the brain and the nervous system. The effect of the endorphins is similar to that of the morphine.  
 
        
                    
             
        
        
        
Through gene expression, transcription and translation of this subset of genes determines how a cell looks and acts—its phenotype. ... | Cell fate means that a stem cell “makes a decision” to differentiate into a more mature cell type.