Answer:
excretory system and circulatory system
Explanation:
Blood is part of circulatory system and as it move through various organs it exchanges the gases i.e give oxygen to the cell and take carbon dioxide from them. After taking CO2, the blood becomes impure and hence it passes through the kidney before going to the heart. Kidney is part of excretory system which removes carbon dioxide from blood and thus purifies it.
Mutation causes change in an organisms DNA, resulting in a change in all aspects of the organisms life. It affects how the organism looks, and how it behaves. If there was no mutation, an organism could not change, therefore there wouldn't be evolution at all.
Answer:
Explanation: Trophic level, also called feeding level, is defined as the feeding level or each stage in a food chain or food web. In other words, trophic level is the number of links by which food energy is transferred from producers to final consumers. For example, in a food chain like the one below, we can have these levels.
Answer:
Im not sure what are the choices?
Explanation:
