Earth's crust is made of rock, and rock is made of natural substances called minerals. There are three main types of rock: sedimentary, igneous, and metamorphic rock. Each type is produced in different ways. The oldest rocks on Earth were formed about 3.8 billion years ago.
The other guy is right, B is the answer now hurry and get that test prep done
I think the anwser is C)
Sorry if its wrong
Thanks
<em>Hugs ~L</em>
Answer:
Plants need a rigid structure. Animal cells have flexible cell membranes. So animal cells can have a variety of shapes, but plant cells can not, they have to take the shape of their cell walls. Both plant and animal cells are eukaryotic, so they contain membrane-bound organelles like the nucleus and mitochondria.
Answer:
Serve to transfer signals between cells.
Explanation:
Intercalated disc also called gap junctions are structural formations that are located between the myocardial cells of the heart. They help to bond or connect cardiac cells fibers together. They also help in cell to cell communications and propagate action potential. They serve to transfer signals between cells.
