1 / 13

Chapter 2

Chapter 2. Living things. Section 1: What is life (Part 1, pages 34-37). Organism = LIVING THING Examples: yourself, a pet, insects, plants ALL LIVING THINGS SHARE THESE CHARACTERISTICS: Cellular organizations Contain similar chemicals Use energy Respond to their surroundings

xenos-love
Télécharger la présentation

Chapter 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 2 Living things

  2. Section 1: What is life (Part 1, pages 34-37) • Organism = LIVING THING • Examples: yourself, a pet, insects, plants • ALL LIVING THINGS SHARE THESE CHARACTERISTICS: • Cellular organizations • Contain similar chemicals • Use energy • Respond to their surroundings • Grow and develop • Reproduce

  3. Cellular Organization • All organisms are made of small building blocks called cells • A cell is the basic unit of structure and function • Cells are so small you need a microscope to see them • Unicellular: single-celled organisms (Bacteria) • Multicellular: composed of many cells that are specialized to do certain tasks • Example: in our body, muscle and nerve cells (work together to keep us alive!)

  4. The Chemicals of life • Cells are composed of chemicals • SUCH AS… • Water (most abundant) • Carbohydrates (energy) • Proteins and lipids/fats (building materials) • Nucleic acid : genetic materials, chemical instructions that direct the cell’s activities

  5. Energy Use • Cells of organisms use energy to do what living things must do • Example: Repairing injured parts • An organisms cells are ALWAYS hard at work

  6. Response to surroundings • Plants and all other organisms react to changes in their environment • STIMULUS: a change in an organism’s surroundings that causes an organism to react • Example: temperature, light, sound…. • RESPONSE: an action or change in behavior • Example: A plant stem growing toward the sun. Stimulus?? Response??

  7. Growth and development • Living things GROW (getting larger) and DEVELOP • Development: the process of change that occurs during an organisms life to produce more complex organisms

  8. Reproduction • Organisms have the ability to reproduce, or produce offspring that are similar to the parents • Example: Robins lay eggs… that develop into young robins… that closely resemble their parents!

  9. Life Comes from life • Living things arise from living things through reproduction • ….But, four hundred years ago people believed that life could appear from nonliving things… CRAZY!?!?! • They called this… SPONTANEOUS GENERATION ***the mistake idea that living things can arise from nonliving sources http://www.youtube.com/watch?v=WNByRghR6sw

  10. Redi’s Experiment • Francesco Redi – Italian doctor (1600’s) • He designed a CONTROLLED EXPERIMENT to show flies do not arise from decaying meat • Who remembers what a controlled experiment is??? • A scientist carries out 2 tests that are identical in every respect except for one factor

  11. Redi’s Experiment • Left jar = UNCOVERED • Right jar = COVERED • Manipulated Variable? • Whether or not the jar Was covered

  12. Pasteur’s experiment • Louis Pasteur--- French chemist (mid-1800s) • Some people still did not believe Redi… so Pasteur came up with a new experiment • His experiment… demonstrated that new bacteria appeared in broth only when they were produced by existing bacteria • Both experiments convinced people that LIVING THINGS DO NOT ARISE FROM NONLIVING MATERIAL

  13. Pasteur’s experiment

More Related