Living things produce offspring of the same species, but in many cases offspring are not identical with each other or with their parents. Plants and animals, including humans, resemble their parents in many features because information is passed from one generation to the next.
B. the oceans is the largest ecosystem.
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.
Compounds contain two or more different elements. Water is a molecule because it contains molecular bonds. Water is also a compound because it is made from more than one kind of element (oxygen and hydrogen) It is not a compound because it is made from atoms of only one element which is oxygen.
