Explanation:
Cancer can kill when it invades essential organs, like your liver, lungs, or brain, and stops them from functioning properly. These complications could be due to primary cancer that starts in an essential organ, such as brain cancer. Or it could be cancer that has metastasized from one area to another.
Classification systems previously were having very different goals than modern classification systems. If we look at old eras, scientists like Aristotle and Theophrastus tried to classify organisms on the basis of apparent characteristics, habitat and simple other traits.
Old classification systems had alot of errors and flaws. For example they classified fish and whale in one group because they lived in water, now we know fish is amphibian while whale is mammal.
So we can say that the goal o earlier classification system were just to make groups of organisms on the basis of External features.
Goal of modern classification system:
Modern classification approach was started by Linnaeus. It focuses more on biological delimitation and evolutionary histories than mere external characteristics. It organizes organisms in groups in such a way that grouping reflects their evolutionary relatedness. It is not just specie level but also focuses on sub-specie and population level classification.
Thus modern goal is better in many terms and is more reliable than old classification goals.
Hope it helps!
Answer:
n unicellular organisms, oxygen diffuses across the cell membrane into the cell. Carbon dioxide diffuses out of the cell once the concentration of carbon dioxide is higher inside the cell than it is outside of the cell. Some micro-organisms, including some bacteria and fungi, can survive without oxygen.
Explanation: