The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary (K–T) extinction) was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago.
Answer:
The Six Kingdoms. When Linnaeus developed his system of classification, there were only two kingdoms, Plants and Animals. But the use of the microscope led to the discovery of new organisms and the identification of differences in cells. Today the system of classification includes six kingdoms.
Explanation:
An energy pyramid is always related to the organisms food web. A increase in no of tropic levels could make it complex. Also the reason for only 4 or 5 is to make it simple to understand.
Answer:
This is the digestive system.
Explanation:
We can tell that this is the digestive system because we can see #1: The stomach, #2: The small intestine, #3: The large intestine, and #4: The liver. Hope this helped!
