Food chains model energy flow through an ecosystem. Producers pump energy into an ecosystem from an environmental source, and this energy is then passed from one organism to the next.
Answer:
Natural selection and selective breeding can both cause changes in animals and plants. The difference between the two is that natural selection happens naturally, but selective breeding only occurs when humans intervene. For this reason selective breeding is sometimes called artificial selection.
Explanation:
Answer:
4
Explanation:
The circulatory system includes the blood that has picked up the carbon dioxide from all of the respiring tissues and who also delivered oxygen to them to continue respiring.
The blood will then reach the lung where the carbon dioxide that the tissues released is exchanged for oxygen in the alveoli.
* Blood cells isn't an organ system which makes 1 incorrect.
* Digestive system will in no way bring the blood to the lungs or away from it. This is the circulatory system's job. So 2 is incorrect.
*Lastly, lungs are organs and the question asks for organ systems. So 3 is incorrect.
Answer: Microscopic organisms are not made of cells.
All things that are living are made of cells.
