1. What is life? Prentice Hall: Life Science (2005), pp. 34-41

2. Objective(s): I can  List the characteristics all living things share.  Explain where living things come from.  Identify what all living things need to survive.

3. Key terms  Organism  Cell  Unicellular  Multicellular  Stimulus  Response  Development  Spontaneous generation  Autotroph  Heterotroph  Homeostasis

4. Key Concepts  What characteristics do all living things share?  What do living things come from?  What do living things need to survive?

5. Introduction  Organisms are living things.  Organisms include: plants, dogs, sharks, sting rays, moss, bacteria, humans, worms, spiders, etc.  Living things in an environment are also referred to as biotic factors.

6. The Characteristics of Living Things  Living things share important characteristics.  Characteristic- a feature or quality that makes somebody or something recognizable  All living things have a cellular organization, contain similar chemicals, use energy, respond to their surroundings, grow and develop, and reproduce.

7. Cellular Organization  All organisms are made of small building blocks called cells.  Cells are the basic units of structure and function in all living things.  Unicellular = one celled organism  Multicellular = hundreds to trillions of cells working together

8. Cells are the building blocks of life.

9. The Chemicals of Life Organism Carbohydrates C, H, O Provide energy Proteins Chemical Reactions Build & repair cells Nucleic Acids Transfer genes Produce proteins Lipids Mostly C, H Fats & Oils Store energy Water H, O Most abundant

10. Energy is the ability to do work and cause change Walking Talking Thinking Breathing Playing Studying All require energy! Where do living organisms get their energy? Living things obtain and use energy

11. Response to environment Organisms respond to the environment around them. What are some common responses to your environment?

12.  Stimulus: A change in the environment that occurs and causes a reaction.  Response: The way an organism reacts to the stimulus

13. Growth and Development  Growth is the process of becoming larger.  Development is the process of change that occurs during an organism’s life to produce a more complex organism.

14. Living things all grow and change. Whether talking about a person or a tree changes will take place as long as the organism is alive.

15. Reproduce  Asexual Reproduction: single organism reproduces without the aid of another  Sexual Reproduction: two cells from different individuals unite to produce the first cell of the new individual

16. All organisms must reproduce-offspring are the result of reproduction.

17. Eliminate Waste  An organism may not use all the nutrients from their energy sources.  The excess materials are eliminated/removed from the organism.

18. Life comes from Life  Living things arise from living things through reproduction.  At one time people believed that life could appear from nonliving material.  This mistaken idea that living things can arise from nonliving sources is called spontaneous generation.  It took hundreds of years to convince people that spontaneous generation does not occur. http://www.dreamstime.com/stock-photo-large-fly-on-a-wall- image10562960

19. Redi’s Experiment An Italian doctor Helped disprove spontaneous generation during 1600s Designed a controlled experiment to show flies don’t arise from decaying meat

20. Pasteur’s Experiment A French Chemist Designed controlled experiments that finally rejected spontaneous generation in the mide- 1800s

21. The Needs of Living Things  Though surprising, flies, bacteria, and all other living things have the same basic needs as you.  All living things must satisfy their basic needs for water, food, living space, substances found in air, and stable internal conditions.

22. Water  All living things need water to survive.  Most organisms can live for only a few days without water.  Organisms need water to obtain chemicals from their surroundings, break down food, grow, move substances within their bodies, and reproduce.

23. http://www.hickerphoto.com/waterfall-pictures-4109-pictures.htm

24. Food  Organisms need a source of energy to live.  Food is used as the energy source.  Some organisms, such as plants, capture the sun’s energy and use it to make food.  Organisms that make their own food are called autotrophs. Auto- means “self” and –troph means “feeder.”

25. Food  Organisms that cannot make their own food are called heterotrophs. Hetero- means “other.”  Heterotrophs obtain their energy by feeding on others.  Some heterotrophs eat autotrophs and use the energy I the autotroph’s stored food.  Other heterotrophs consume heterotrophs that eat autotrophs.  Therefore, heterotroph’s energy source is also the sun- but in an indirect way.

27. Living Space  All organisms need a living space- a place to get food and water and find shelter.  Whether an organism lives in the freezing Antarctic or the scorching desert, its surrounding must provide what it needs to survive.  Because there is a limited amount of space on Earth, some organisms must compete for space.

29. Stable Internal Conditions  Organisms must be able to keep the conditions inside their bodies stable, even when conditions in their surroundings change significantly.  The maintenance of stable internal conditions is called homeostasis.  Homeostasis keeps internal conditions just right for cells to function.

30. Stable Internal Conditions  Think about your need for water after a hard workout.  When water levels in your body decrease, chemicals in your body send signals to your brain, causing you to feel thirsty.  Other organisms have different mechanisms for maintaining homeostasis.

31. Homeostasis

32. Summary  All living things share common characteristics.  All living things have basic needs in order to survive.  Redi and Pasteur designed experiments to disprove spontaneous generation.  Life comes from life.