Characteristics of Living Things

1. Characteristics of Living Things Life Science Biology

2. When you see the symbol, write down the definition from the slide.

3. Objectives • Be able to determine whether something is a living thing or a non-living thing. • Learn and understand the 6 main characteristics of living things.

4. Video Clip • The Science of Life: Characteristics of Living Things • http://videos.howstuffworks.com/hsw/17201-the-science-of-life-characteristics-of-living-things-video.htm

5. Organism • Organism-a living thing; anything that can carry out life processes independently. They can be unicellular (one cell) or multicellular (many cells). • Some cells have organelles and some do not.

6. First Characteristic of Living Things • The first characteristic of living things is that they are all composed of cells. They can be Uni or multicellular. • Some cells have organelles.

7. Second Characteristic of Living Things • The second characteristic of living things is that they have DNA. • When organisms reproduce they pass copies of their DNA to their offspring.

8. Third Characteristic of Living Things • The third characteristic of living things is all living things use energy. Plants however use the sunlight to obtain their energy. Animals and humans eat food to obtain their energy.

9. Energy • All organisms use energy to undergo life processes. Energy cannot be reused or recycled. In nature, materials needed by all organisms in an ecosystem are reused or recycled.

10. Nitrogen, carbon, oxygen and other nutrients move through ecosystems in a predictable pattern or cycle. These nutrient cycles in nature are called biochemical cycles.

11. Inorganic compounds • Water, carbon dioxide, ammonia and oxyen are the basic inorganic chemicals of life. Th formulas for each are; • Water- H2O • Carbon-CO2 • Ammonia-NH3 • Oxygen- O2

12. Organic compounds The organic compounds of life include; • carbohydrates • Lipids • Proteins • nucleotides They are called organic because all contain the compound element Carbon.

13. Carbohydrates • Any of a group of organic compounds that includes sugars, starches, celluloses, and gums and serves as a major energy source in the diet of animals.

14. Lipids • Any of a group of organic compounds, including the fats, oils, waxes, sterols, and triglycerides, that are insoluble in water

15. Proteins • made up of amino acids. Proteins are basic components of all living cells and are therefore among the principal substances that make up the body.

16. Nucleotides • Any of various compounds consisting of a nucleoside combined with a phosphate group and forming the basic constituent of DNA and RNA

17. Oxygen cycle-the process by which oxygen released into the atmosphere by photosynthetic organisms is taken up by aerobic organisms while the carbon dioxide released as a by-product of respiration is taken up for photosynthesis.

18. Carbon cycle- The continuous process by which carbon is exchanged between organisms and the environment.

20. Nitrogen cycle-the circulation of nitrogen; nitrates from the soil are absorbed by plants which are eaten by animals that die and decay returning the nitrogen back to the soil

22. Fourth Characteristic of Living Things • The fourth characteristic of living things is homeostasis. • This is maintaining the inside of their bodies. • Eating the right foods and staying clean are parts of this maintaining process.

23. Regulation of an organism’s internal surroundings (environment) involves sensing the internal and external environment and changing physiological activities to keep condition within the range required to survive.

24. Let’s discuss the things that can effect the way we respond to our environment.

25. Environment • the air, water, minerals, organisms, and all other external factors surrounding and affecting a given organism at any time.

26. Homeostasis • Homeostasis - the body’s ability to maintain a relatively constant internal environment despite changes in the external environment.

27. Feedback mechanisms • Homeostasis maintained through either: • Negative feedback mechanisms • opposes response to stimulus • Positive feedback mechanisms • enhances response to stimulus

28. Stimulus • Stimulus- something that causes a reaction in a living thing

29. Response • A reaction, as that of an organism or any of its parts, to a specific stimulus

30. Plants • Animals and plants respond in different ways. Let’s look at the way plants respond to their environment.

31. Tropism • A plant’s responses to gravity, moisture, and light are called tropisms. Tropisms can be either negative or positive. Let’s look each one.

32. Negative tropism • Negative tropism- Moving or turning away from a stimulus, such as light

33. Positive tropism • Positive tropism is when there is movement toward the source of stimulation.

34. Fifth Characteristic of Living Things • The fifth characteristic of living things is that all living things grow and develop. Cell growth can include size of cell or number of cells.

35. Development refers to the series of changes that produces a more complex organism. • Growth is an increase in size.

36. Sixth Characteristic of Living Things • The sixth characteristic of living things is reproduction. All living things need to reproduce to survive.

37. Reproduction is sexual and/or asexual. • Sexual reproduction-reproduction in which the sex cells from two parents unite, producing offspring that share traits from both parents. • Asexual reproduction-reproduction that does not involving the union of sex cells and in which on parent produces offspring identical to itself.

38. Living or Non-living and Why? Living Non-Living Living Non-Living Living Non-Living

39. Six Characteristics of Living Things • Cells • Have DNA • Uses energy • Homeostasis/responds to environment • Growth and Development • Reproduction