D is the correct answer i believe hope this helps!!
Plz mark as brainlist and five star it would mean alot!!!
Mitocondria is nicknamed the powerhouse of the cell, These structures are nicknamed the powerhouse of the cell because they work to convert energy into forms that the cell is able to use. Mitochondria are semi-autonomous cells, which means that they only rely partly on the cell for division and growth.
-www.reference.com/science/powerhouse-cell-f9bbce99417d7167
After all this info you have given me, the correct one is Keystone species. As defined in sources like National Geographic, <span> These are types of plants or animals that play a unique and crucial role in the way an ecosystem functions. Without </span>keystone species<span>, the ecosystem would be dramatically different or cease to exist altogether. I hope this helps you a lot </span>
Answer:
A
Explanation:
hydrogen bond always occur between H and O
Answer:
The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature and pH, and maintain homeostasis.
There are two main types of circulatory systems: 1. open circulatory systems and closed circulatory systems. Open circulatory systems are systems where internal organs and body tissues are surrounded by circulatory fluid. This fluid is called hemolymph, and it's pretty much like blood, except that it doesn't contain oxygen transporting cells.
2. The closed circulatory system of some mollusks and all vertebrates and higher invertebrates is a much more efficient system. Here blood is pumped through a closed system of arteries, veins, and capillaries. Capillaries surround the organs, making sure that all cells have an equal opportunity for nourishment and removal of their waste products. However, even closed circulatory systems differ as we move further up the evolutionary tree.
