Valence electrons are the electron on the outer energy level and they are important because they tell if that element is compatable
I think the correct answer would be A. The yolk sac becomes the placenta. It is membranous sac that is attached to the embryo. It provides all the nutrition and the blood cells needed by the embryo. It is also called the umbilical vesicle.
Answer:
B. A sperm cell
Explanation:
Meiosis creates gametes/sex cells, such as the sperm and egg.
So, sperm cells are formed by meiosis.
Meiosis doesn't create fertilized eggs, it instead creates normal egg cells.
Meiosis also doesn't create heart and bacterial cells because those are made in mitosis.
So, B is the correct answer.
