Some species of penguins, such as chinstrap penguins, depend on open water for their survival. Other species of penguins, such as Adélie penguins, depend on ice. Over the last 20 years, the population size of chinstrap penguins has increased, and the population size of Adélie penguins has decreased. An increase in global air and water temperatures likely caused <span>these changes in population size.</span>
Answer:
1. A massive star depletes its nuclear fuel; gravity overpowers the star; supernova occurs; core of star collapses
2. black hole; gravitational pull
3. The center of the Milky Way
Explanation:
In general, the term organelle is used for the small structures within a cell.