| Questions | 5 |
| Topics | Cytoplasm, Light Waves, Medulla, Spinal Cord, Work |
The nucleus of a eukaryotic cell contains the genetic material of the cell and is surrounded by cytoplasm which contains many organelles. These include:
| Organelle | Function |
|---|---|
| ribosomes | produce proteins |
| mitochondria | produce energy |
| endoplasmic reticulum | helps synthesize proteins and fats |
| Golgi apparatus | prepare proteins for use |
| lysosomes | help the cell manage waste |
| centrosomes | guide cell reproduction |
Unlike mechanical sound waves that require a physical medium for propagation, light waves are electromagnetic and can travel through empty space. Light waves are also much faster, travelling at 186,000 m/s vs. 343 m/s for sound waves.
Part of the brainstem, the medulla is the connection between the brain and the spinal cord. It controls involuntary actions like breathing, swallowing, and heartbeat.
The spinal cord connects the brain to the body's network of nerves. It carries impulses between all organs and the brain and controls simple reflexes.
Work is performed on an object when an applied force causes displacement along the same vector. Measured in joules (J) or newton-meters (Nm), work is calculated by multiplying force times displacement: \(W = \vec{F}\vec{d}\)