When blood is in the lungs,
where oxygen is plentiful, oxygen easily binds to the first subunit and then quickly fills up the remaining ones. Then, as blood circulates through the body, the oxygen level drops while that of carbon dioxide increases. In this environment, hemoglobin releases its bound oxygen.
I think the correct answer would be the last option. Monozygotic twins are identical, while dizygotic twins are fraternal. Identical twins involves developing from one zygote where it splits, forming two embryos so that the twins would have more or less the same characteristics. This type of twins can share the same amniotic sac depending on the time the fertilized egg is divided. On the other hand, fraternal twins developed from two eggs wherein they are being fertilized by two different sperm cells resulting to twins which has different characteristics. For this type, the two fertilized eggs would develop separate amniotic sacs.
Answer:
the answer is b.The model should show the original stem cell dividing to become a differentiated cell and another stem cell.
Explanation: