1. Cells in Action

2. Diffusion Movement of particles from areas of high concentration to areas of low concentration Osmosis The diffusion of water through a semipermeable membrane Semipermeable means only certain substances can pass through

4. Permeable

6. Semipermeable

8. Nonpermeable

14. Cell Energy Photosynthesis Process by which plants use sunlight to make food converts carbon dioxide and water into glucose and oxygen 6CO₂ + 6H₂O C₆H₁₂O₆ + 6O₂ Cellular Respiration Process by which plants use oxygen to produce energy Sun’s energy

15. Cell Energy Photosynthesis 6CO₂ + 6H₂O C₆H₁₂O₆ + 6O₂ Cellular Respiration Process by which plants use oxygen to produce energy C₆H₁₂O₆ + 6O₂ 6CO₂ + 6H₂O + Energy Sun’s energy

16. CO₂ + H ₂O C₆H₁₂O₆ + O₂ ATP Light Energy Photosynthesis Cellular Respiration

17. Cell Energy Fermentation Bacteria in yeast cause CO₂ This makes bread rise Running Caused by a lack of oxygen Muscles build up lactic acid Cause a burning in the muscle

18. The Cell Cycle The life of a cell is called the cell cycle The cycle begins when the cell is formed The cycle ends when the cell divides to form new cells Prokaryote divide in a process called binary fission Eukaryotic cells divide to form two identical cells in a process called mitosis

19. The Cell Cycle Before dividing DNA is copied DNA forms into chromosomes Chromosomes are two exact copies of the DNA There are 23 pairs or 46 chromosomes in humans Potatoes have 24 and 48

21. The Cell Cycle Chromosomes are two exact copies of the DNA There are 23 pairs or 46 chromosomes in humans Potatoes have 24 and 48 Ophioglossum reticulatum has 1,260 chromosomes Plants cells divide differently because of their cell wall The form a plate between the two new cells