Exploring Characteristics of Living Organisms

1. Chapter 1: Characteristics of Living Organisms

2. Chapter 1 Introduction • All living things have certain characteristics that they share. Although there are many differences between some living things, there are some traits that all living organisms have in common. What are some characteristics that living things share? What is the most important of these characteristics? What are some examples of living and non-living things? How are they similar? How are they different?

3. Section 1: Objectives • Describe the 6 characteristics of living things. • Describe how organisms maintain stable internal conditions. • Explain how asexual reproduction differs from sexual reproduction.

4. Characteristics of Living Things • 1.Living things have cells. • Cells: membrane-covered structure that contains all of the materials necessary for life • How many cells do you have? • Why are they important?

5. Characteristics of Living Things • 2. Living things sense and respond to changes in their environment. • Stimulus: anything that causes a reaction or change in an organism or any part of an organism • Stimuli can be: • Chemicals • Gravity • Light • Sounds

6. Characteristics of Living Things • Even though an organisms outside environment may change, their internal environment must remain constant. • Homeostasis: the maintenance of a stable internal environment

7. Characteristics of Living Things • Organisms must respond to external changes in their environment. • When animals are cold, what is one way that they respond to this change? • When animals are hot, what is one way that they respond to this change?

8. Characteristics of Living Things • 3. Living things reproduce. • Organisms make other organisms similar to themselves. • They do this in one of 2 ways: • Sexual reproduction: 2 parents produce offspring • Asexual reproduction: single parent produces offspring

9. Characteristics of Living Things • 4. The cells of all living things contain DNA (deoxyribonucleic acid) • When organisms reproduce, they pass copies of their DNA onto their offspring.

10. Characteristics of Living Things • 5. Organisms use energy to carry out the activities of life. • These activities include: • Making food • Breaking down food • Moving materials into and out of cells • Metabolism: the sum of all chemical processes that occur in an organism

11. Characteristics of Living Things

12. Characteristics of Living Things • 6. Living things grow and develop. • Whether an organism is unicellular or multicellular, it grows and develops. • In addition to getting larger, living things may develop and change as they grow.

13. Chapter 2 Section 1 Recap • 1)List the 2 of the 6 characteristics of living things. • 2) Give 4 examples of stimuli. • 3) Does an organism want its internal environment to change? Explain your answer. • 4) T/F Organisms must never respond to changes in their external environment. Explain your answer. • 5) What do organisms use energy to do? • 6) T/F Living things grow and develop.

14. Section 2: Objectives • Explain why organisms need food, water, air, and living space. • Describe the chemical building blocks of cells.

15. Section 2: The Necessities of Life • Living organisms need many things in order to survive: • Water • Air • Shelter • Food

16. The Necessities of Life • 1. Water • Your cells are made up to 70% water. • Most of the chemical reactions in your body require water. • Different organisms require different amounts of water.

17. The Necessities of Life • 2. Air • Air is a mixture of several different gases, including oxygen and carbon dioxide. • Organisms living on land get oxygen from air. • Organisms living in water take in dissolved oxygen or come to the water’s surface to get oxygen from the air.

18. 3. Shelter All organisms need a place to live that contains everything they need to survive. Space on Earth is limited. What does this mean for organisms? The Necessities of Life

19. The Necessities of Life • 4. Food • All living things need food. • Food gives organisms energy to carry on life processes. • Not all organisms get food the same way: • Producers: make their own food • Consumers: eats other organisms or organic matter • Decomposer: eats dead/decaying organisms

20. The Necessities of Life • Nutrients are made up of molecules. • A molecule is a substance made up of one or more atoms. • Molecules of different atoms combine to make compounds. • Atoms  Molecules  Compounds

21. Chapter 1 Sec. 1-2 Recap • 1) List 4 of the 6 characteristics that living organisms share. • 2) T/F Organisms must respond to external changes in their environment. • 3) What do organisms use energy for? • 4) List the 4 necessities of life. • 5) Why do organisms depend on water?

22. The Necessities of Life • Almost all life processes of a cell involve proteins. • Proteins: molecules made up of amino acids • Amino acids are the subunits of proteins. • Some proteins are made up of only a few amino acids, while others are made up of many.

23. The Necessities of Life • Molecules made up of sugar are called carbohydrates. • Cells use carbohydrates as a source of energy and for energy storage. • Simple carbohydrates are made up of one or a few sugar molecules linked together. • Complex carbohydrates are made of hundreds of sugar molecules.

24. The Necessities of Life • Lipids: compounds that cannot mix with water • Lipids store energy and form the membranes of cells. • Phospholipids as well as fats and oils are classified as lipids.

25. The Necessities of Life • The head of a phospholipid is attracted to water but the tail is not. • Hydrophilic: attracted to water (“water-loving”) • Hydrophobic: not attracted to water (“water-hating”)

26. The Necessities of Life

27. The Necessities of Life • ATP: Major energy carrying molecule of the cell. • Energy in carbohydrates and lipids must be transferred to ATP. • This then fuels the cell. • ATP: Adensosine Tri-Phosphate

28. The Necessities of Life • Nucleic acids: “Blue-prints” of life. • Contain all information needed for a cell to make proteins. • Made up of nucleotides. • Example: DNA

29. Chapter 1 Sec. 1-2 Recap • 1) What is a stimulus? • 2) What does food give organisms? • 3) What do cells use carbohydrates for? • 4) List 2 things that lipids do. • 5) __________ make up cell membranes. • 6) What is the difference between hydrophilic and hydrophobic?

30. Chapter 1 Vocabulary Review • 1) ____: living things that are made up of only 1 cell • 2) ____: things that have all the characteristics of life • 3) ____: an organism’s ability to maintain steady internal conditions when outside conditions change • 4) ____: a light microscope that uses more than 1 lens to magnify an object

31. Chapter 1 Vocabulary Review • 5) _____: living things that are made up of more than 1 cell • 6) _____: the smallest unit of life • 7) _____: uses light and lenses to enlarge the image of an object • 8) _____: use a magnetic field to focus a beam of electrons through an objector onto an object’s surface

32. Chapter 1 Vocabulary Review • 9) List the 6 characteristics of living things.

33. Chapter 1 Vocabulary Review • 10)Plants are multi-cellular organisms. Why do multi-cellular organisms grow larger in size over time? In your response, include how growth and development relate to this process.