To calculate the variance, subtract your actual fixed overhead cost from your standard overhead cost. If the actual cost is higher than the fixed cost, the cost variance is unfavorable. For example, your standard fixed overhead cost is $3 per unit.
The major role of hemoglobin is to carry oxygen from the lungs to the tissues and return carbon dioxide (CO2) from the tissue to the lungs.
Hemoglobin in the blood carries oxygen from the respiratory organs (lungs or gills) to the rest of the body (i.e. the tissues). There it releases the oxygen to permit aerobic respiration to provide energy to power the functions of the organism in the process called metabolism.