Unicellular organisms excrete waste by a contractile vacuole. A vacuole is membrane-enveloped organelle in a cell that is found in lots of microorganism. It expands, filling with water then contracts, removing all of its contents to the exterior of the cell.
Answer:
A reaction that joins the nuclei of two atoms into one
Explanation:
Think of the words "nuclear fusion".
Nuclear = "relating to a nucleus"
Fusion = "joining"
So, nuclear fusion is the joining of two nuclei into one.
A and B are wrong, because chemical reactions involve electrons.
D is wrong, because the splitting of a nucleus is fission.
The answer is Physical Property
Explanation:
The circulatory and respiratory systems work together to circulate blood and oxygen throughout the body. Air moves in and out of the lungs through the trachea, bronchi, and bronchioles. Blood moves in and out of the lungs through the pulmonary arteries and veins that connect to the heart.