| Questions | 5 |
| Topics | Cell Membrane, Cytoplasm, Mass vs. Weight, Number System, Periods |
Animal cells are surrounded by a semipermeable membrane which allows for the transfer of water and oxygen to and from the cell. In plant cells, the cell membrane is surrounded by a somewhat rigid cell wall which provides the cell structure and support.
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 |
Mass is the amount of matter something has while weight is the force exerted on an object's mass by gravity. So, although a person's mass doesn't change when going from the Earth to the Moon, their weight will decrease because the force of the Moon's gravity is much less than that of Earth.
The metric system is a number system that designates one base unit for each type of measurement. For example, the base unit for length is the meter and the base unit for mass is the gram.
The rows of the Periodic Table are called periods and contain elements that have the same number of electron shells ordered from lower to higher atomic number.