Topic: Cell Biology (Cell Fractionation)
Cellular fractionation uses differential centrifugation to separate organelles based on their size and density.
Steps:
Understanding the Question: We need to identify which organelle is heavy enough to settle (pellet) at a relatively low speed of 1000g.
Key Formulas and Approach: Larger and denser particles sediment faster at lower gravitational forces ($g$). Smaller particles require much higher speeds.
Detailed Solution:
At the lowest speed (1000g), the largest and heaviest components like the Nucleus and whole cells settle first.
At medium speeds ($\sim 10,000-20,000g$), mitochondria and lysosomes pellet.
At very high speeds ($\sim 100,000g$), microsomes (ER fragments) and small vesicles settle.
Ribosomes, being the smallest, require the highest speeds and longest times to pellet.