True/False Indicate whether the sentence or statement is true or false. |
| 1. | Robert Hooke observed cork cells under a microscope. |
| 2. | Anton van Leeuwenhoek concluded that all plants are composed of cells. |
| 3. | All living things are composed of many cells. |
| 4. | A cell is the smallest unit that can carry on all the processes of life. |
| 5. | Inside smaller cells, materials and information can be transported more quickly. |
| 6. | Membranes are selectively permeable if they allow only certain substances to diffuse across them. |
| 7. | Lysosomes carry on cellular respiration. |
| 8. | Microtubules and microfilaments form the cytoskeleton of cells. |
| 9. | Colonial organisms differ from single-celled organisms in that each cell cannot support its own existence. |
Completion Complete each sentence or statement. |
| 10. | The statement that “cells are produced only from existing cells” is part of the ____________________. |
| 11. | The ratio of surface area to volume puts limitations on a cell’s ____________________. |
| 12. | Eukaryotic cells are much larger and have more specialized functions than prokaryotic cells because they contain ____________________ which take up space and carry out specialized activities. |
| 13. | A cell with a well-defined nucleus surrounded by a nuclear membrane is called a(n) ____________________ cell. |
| 14. | A cell membrane is said to be ____________________ permeable because it allows the passage of some solutes and not others. |
| 15. | ____________________ molecules have “heads” and “tails” and are found in the cell membrane. |
| 16. | Scientists have discovered that cells contain smaller specialized structures known as ____________________. |
| 17. | The spherical organelles that are the site of protein synthesis in a cell are the ____________________. |
| 18. | The meshlike network of protein fibers that supports the shape of the cell is called the ____________________. |
| 19. | The fluid portion of the cytoplasm is called the ____________________. |
| 20. | Photosynthesis takes place in the ____________________ of plant cells. |