It’s cell wall and chloroplast. We don’t need chloroplast because we don’t make our own food.
Answer:
Option 4 - Calcium
Explanation:
The <em>divalent cation </em>called <em>calcium</em> is needed to provide additional support to the bone matrix.
Calcium is considered one of the most <em>important components</em> in bone development. It helps in the formation as well as maintenance of bone. During the modeling and remodeling process of bones, calcium facilitates the formation of <em>semi-hard new tissues</em> which leads to the formation of new bone which is very hard.
Due to this reason, calcium is needed to create extra bone matrix support.
There is no element with one valence electron and six energy levels. Only two valence electrons and six energy levels.
Answer:
Calcium
Explanation:
A: Calcium is a group 2 element with two valence electrons. Therefore, it is very reactive and gives up electrons in chemical reactions. It is likely to react with an element with six valence electrons that “wants” to gain two electrons. This would be an element in group 6, such as oxygen.
Answer:the decline of lichens is an important indicator of an imbalance in the ecosystem. this research can help system ecologists predict how pollution will affect the entire ecosystem
Explanation: