A group of organs would be an organ system so perhaps B
Iron is a key component of hemoglobin. Hemoglobin the the protein responsible for transporting oxygen uses iron to bond oxygen. Additionally Hemoglobin is a key component of RBC (erythrocytes)... If iron is deficit the body is not able to produce red blood cells and it can result in iron deficient anemia.
Answer:
Photosynthesis replace CO2 with O2 in the atmosphere. Plants prepare their food by this process.
The burning of hydrocarbon in the presence of O2 is called combustion.
CH4. + O2-----------> CO2. + H2O + Heat
Hydrocarbons undergo combustion.
Geology is yhe branch of science which deals with the study of earth. The person that studies geology is geologist.
Explanation:
I think gills
but idk so don't fully take my word on it
I am pretty sure it would be more difficult ok Jupiter
