Grade 11 Biology DP Assignment 3 Cells

1. Grade 11 Biology DPAssignment 3Cells

2. Section 7.1 Summary – pages 171-174 The History of the Cell Theory • Before microscopes were invented, people believed that diseases were caused by curses and supernatural spirits. • As scientists began using microscopes, they quickly realized they were entering a new world–one of microorganisms. • Microscopes enabled scientists to view and study cells, the basic units of living organisms.

3. Section 7.1 Summary – pages 171-174 The cell theoryis made up of three main ideas: All organisms are composed of one or more cells. The cell is the basic unit of organization of organisms. All cells come from preexisting cells.

4. Section 7.1 Summary – pages 171-174 Development of Electron Microscopes There are two basic types of electron microscopes. The scanning electron microscope scans the surface of cells to learn their three dimensional shape. • The transmission electron microscope allows scientists to study the structures contained within a cell.

5. Summary Section 2 – pages 175-178 All living cells must maintain a balance regardless of internal and external conditions. Survival depends on the cell’s ability to maintain the proper conditions within itself.

6. Summary Section 2 – pages 175-178 It is the plasma membrane’s job to: • allow a steady supply of glucose, amino acids, and lipids to come into the cell no matter what the external conditions are. • remove excess amounts of these nutrients when levels get so high that they are harmful. • allow waste and other products to leave the cell.

7. Summary Section 2 – pages 175-178 This process of maintaining the cell’s environment is called homeostasis. Selective permeabilityis a process used to maintain homeostasis in which the plasma membrane allows some molecules into the cell while keeping others out.

8. Section 2 Check It is fluid because the phospholipid molecules move within the membrane. Proteins in the membrane that move among the phospholipids create the mosaic pattern.

9. A prokaryotic cell does not have internal organelles surrounded by a membrane. Most of a prokaryote’s metabolism takes place in the cytoplasm. 3. Plasma membrane 2. DNA 1. Ribosomes 4. Cell wall Chapter Assessment

10. This eukaryotic cell from an animal has distinct membrane-bound organelles that allow different parts of the cell to perform different functions. 1. Nucleus 2. Nucleolus 3. Chromosomes 4. Plasma membrane 5. Organelles Chapter Assessment