Cnidarians were the first phylum that scientists saw tissue level organization in. Tissue level organization meaning cells all of one type start to function in a unified way.
        
                    
             
        
        
        
Aldosterone increases the reabsorption of sodium ions bringing more back into the blood. 
<span>This is the main mineralocorticoid hormone of the adrenal gland. The function of the aldosterone is in the homeostatic regulation of blood pressure, plasma sodium (reabsorption) and potassium levels (excretion).</span>
        
             
        
        
        
<span>Human weight at the time of birth is influenced by stabilizing selection. Stabilizing selection, also known as negative selection, purifying selection or normalizing selection, is a type of natural selection in which genetic diversity decays according to a particular value of the character. This is the most common mechanism of action of natural selection.</span>
        
             
        
        
        
Lasts are used for photosynthesis .
They have a double membrane around them.
The space inside is called the stroma. The space may contain starch grains and lipid bodies.
In the stroma are structures called thylakoids.
The thylakoids are stacked to form structures called grana.
The grana contain the pigment chlorophyll along with some secondary pigments.