Cells and Heredity: Chapter 1 Section1

1. Cells and Heredity: Chapter 1 Section1 • Learning Targets: • 1. I can explain how living things are different from nonliving things. • 2. I can describe how the microscope led to the discovery of cells. • 3. I can describe the cell theory

2. Living Things are Different From Non-living Things • Any individual form of life that uses energy to carry out its functions is an organism Living things share these basic four characteristics: • 1. Organization • 2. Grow and Develop • 3. Respond to its surroundings (environment) • 4. Reproduce

3. Living Things are Different From Non-Living Things • An organisms body must be organized in a way that enables it to meet its needs. • Ex. – A kingfisher has wings for flying, a heart for pumping blood, and eyes for seeing. • Another characteristic for most organisms is that they grow and develop • Organisms also respond to the world outside of them.

4. Needs of Life • All organisms need energy, materials, and living space to carry out daily life activities. • The energy used by almost all forms of life on Earth comes from the Sun • Materials could be oxygen, shelter, carbon dioxide, water, etc.

5. All Living Things Are Made of Cells • The cell is the smallest unit of a living thing. • Organisms made up of a single cell are called unicellular organisms. • Unicellular organisms are usually to small to be seen directly. • Organisms made up of many cells are called multi-cellular organisms. • Ex. – Water Lily, Frog • Multi-cellular organisms have different types of cells that make up their body parts.

6. Unicellular Organisms Euglena Paramecium

7. The Microscope Led to the Discovery of Cells • Most cells are microscopic • A microscope is an instrument which makes an object appear bigger. • Robert Hooke and Anton van Leeuwenhoek were among the first people to see cells. • Robert Hooke looked at dead cells of a cork (tree bark) • Anton Van Leeuwenhoek was one of the first people to describe living cells. • Leeuwenhoek looked at a drop of pond water under a microscope.

8. Robert Hooke & Anton van Leeuwenhoek Anton van Leeuwenhoek Robert Hooke

9. Robert Hooke - Cells

10. Cells Come From Other Cells • The three concepts of the cell theory are: • 1. Every living thing is made of one or more cells. • 2. Cells carry out the functions needed to support life. * 3. Cells come from other living cells

11. The Cell Theory is Important to the Study of Biology • A scientific theory is a widely accepted explanation of things observed in nature. • A theory must be supported by evidence, including experimental evidence and observations • A theory can prove its value when it explains new discoveries and observations

12. Louis Pasteur • Pasteur observed that milk that turned sour contained large numbers of single celled organisms called bacteria. • He developed a process, now known as pasteurization, in which heat is used to kill bacteria

13. Pasteur’s Test

14. Redi’s Test Francesco Redi also helped to disprove spontaneous generation with this experiment.

15. Bacteria and Spontaneous Generation • In a process known as spontaneous generation, scientists once believed that bacteria grew from non-living materials. • Pasteur conducted an experiment that disproved spontaneous generation. • Pasteur began his experiment with sealed flasks containing broth. • In the first experiment, the flask remained sealed while in the second experiment, the top of the flask was broken to expose the contents to air. • Bacteria grew in only the second flask

16. Bacteria Cells