Tell me some facts about hemoglobin with the given text as a reference

Context: Hemoglobin, abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells  of almost all vertebrates  as well as the tissues of some invertebrates.Hemoglobin in blood carries oxygen from the respiratory organs to the rest of the body. There it releases the oxygen to permit aerobic respiration to provide energy to power functions of an organism in the process called metabolism. A healthy individual human has 12 to 20 grams of hemoglobin in every 100 mL of blood.

Answer: 1. Hemoglobin/Hb/Hgb is the iron-containing oxygen-transport metalloprotein which is present
in red blood cells (erythrocytes) of almost all vertebrates (the exception being the fish
family  Channichthyidae ) as well as the tissues of some invertebrates
2. Hemoglobin carries oxygen in blood from respiratory organs (e.g. lungs or gills) to rest of the
body(i.e. tissue).
3. Metablolism is the energy to power functions of an organism. Hemoglobin releases the oxygen
to permit aerobic respiration .
4. Healthy human have 12 to 25 grams of hemoglobin in every 100 mL of blood.