1. Cell Theory & Microorganisms Study Guide Questions & Answers

2. Hans & Zacharias Janseen
1. Before the 16th Century, what 2 practices did doctors use to help with illnesses & diseases? Bloodletting & Leeches
2. Who invented the compound microscope?
Hans & Zacharias Janseen
3. Tissues are a group of similar cells that all do the same sort of work.

3. 4. What item did Robert Hooke look at, under a microscope, to discover cells? Cork
5. Many celled organisms are not just mixed up collections of different types of cells. 6. How many chromosomes are in a human cell? 46

4. 7. What are the 5 levels of organization
7. What are the 5 levels of organization? Cells---˃ Tissues---˃ Organs---˃ Organ Systems---˃ Organisms
8. What are the 3 components of the CELL THEORY? 1-The cell is the most basic unit of life. 2- All living things or organisms are made of one or more cells. 3- All cells arise from pre- existing, living cells.

5. 9. Why are cells organized
9. Why are cells organized? Cells are organized so they can work together.
10. What are organ systems? Organ systems are a group of organs working together to do a certain job. 11. Which scientist first discovered cells? Robert Hooke 12. From what organelle does a cell get its energy? And HOW? Mitochondria and through the process of energy production.

6. 13. What does DNA stand for? Deoxyribonucleic Acid
14. Prokaryote cells are older, lack a true nucleus, smaller & unicellular. 15. Eukaryote cells are human, animal, plant, fungi, and protist cells; have a nucleus with special structures called organelles & are multicellular.

7. 16. How are organisms categorized
16. How are organisms categorized? All organisms are categorized into one of two groups based on cell type.
17. Microorganism- Any organism too small to be viewed by the unaided eye. 18. Protozoa- Protozoans are simple organisms, or living things. Most protozoans are so tiny that they can be seen only with a microscope.

8. 19. Bacteria- A very large group of microorganisms comprising one of the three domains of living organisms. They are prokaryotic, unicellular, and either free-living in soil or water or parasites of plants or animals.
20.Organelle- tiny specialized structures within a cell that perform cell functions.

9. 21. Vacuole- small fluid-filled sacs that store water, food & waste 22
21. Vacuole- small fluid-filled sacs that store water, food & waste 22. Unicellular- made up of only one cell 23. Nucleus- It is the control center of the cell that is covered with a membrane 24. Cytoplasm- gel like substance that contains all of the organelles and provides the space for cell functions to occur

10. 25. Mitochondria- produces much of the cells energy it needs to function 26. Multicellular- made up of many cells that are dependent on each other to perform essential functions

11. 27.Chromosomes- thread like structure found in both plant & animal cells; are made of protein & contain one molecule of DNA
28. Chloroplast- An organelle that contains a pigment called chlorophyll

12. 29. Cell wall- surrounds the cell membrane and provides support
30. Cell membrane- outer wall of an animal cell