Answer: Hemoglobin
Explanation: Hemoglobin is a protein very rich in iron found in red blood cells and is responsible for the transportation of Oxygen from the lungs to the whole body. Oxygen binds to the hemoglobin in red blood cells and the red pigmentation of blood that is highly oxygenated is due to the hemoglobin content found in RBC's.
III. enzyme pathways in the mitochondria produce ATP in a process that requires oxygen.
Answer:
A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus thereafter replicates as part of the host cell's DNA.
Three of the major characteristics used to classify organisms are cell structure, mode of nutrition and cellularity. These characteristics help scientists determine how organisms are similar to each other as well as how they are different from each other.
Classifying an organism according to its cell structure means determining if it is a prokaryote or eukaryote and then determining if the organism has a cell wall or other organelles, according to Dave Krupp of the University of Hawaii .
Mode of nutrition refers to how an organism gets its food. Organisms can be classified as autotrophs or heterotrophs. Autotrophs make their own food, while heterotrophs must eat other organisms to survive. If an organism is an autotroph, it can also be classified as a photoautotroph or a chemoautotroph. Stephen T. Abedon of Ohio State explains that photoautotrophs produce their own food using energy from sunlight. Chemoautotrophs produce food using the energy from electron-donating compounds.
Cellularity refers to how many cells an organism has and how those cells are arranged. Some organisms are single-celled, while others are multicellular. Advanced organisms have cells organized into tissues.
