1. Multicellular Organisms Cell Teamwork: The Processes of Life

2. Objectives At the end of this PowerPoint, you will be able to: Explain the common problems that multicellular organisms have. Identify body systems in these organisms that allow them to function as a multicellular organism. Show how these complex systems work together to carry out the vital functions of life.

3. CONTENTS Body Organization What Cells Need Transportation of Materials Obtaining Nutrients Gas Exchange Excretion Movement Control Protection Reproduction

4. Body Organization At first an organism like a human appears to be this complicated pile of organs. Those organs make up the organ systems of the body. But first, let’s look at how life is organized from the bottom up.

5. Levels of Organization Atom Molecule Organelle Cell Tissue Organ Organ System Organism

6. How to Be a Multicellular Organism Let’s look at the difficulties in being made up of more than 1 cell and how the body systems are organized to make it all work. CONTENTS

7. What Cells Need All cells, whether alone or part of a larger organism, do the same processes. Cell CONTENTS

8. Unicellular Organisms A protist is surrounded by water, food, and oxygen. Materials just diffuse in and out of the cell. Nutrients Oxygen Waste Protist

9. What Cells Need Thus all cells need the same materials and… Excrete the same waste products. Nitrogen (proteins) Oxygen Gas (O 2 ) Nitrogen Waste Protist Carbon Dioxide (CO 2 ) Water

10. Diffusion – How Chemicals Move A protist is surrounded by water, nutrients, and oxygen. Materials just diffuse in and out of the cell. Nitrogen (proteins) Oxygen Gas (O 2 ) Nitrogen Waste Protist Carbon Dioxide (CO 2 ) Water

11. Diffusion – How Chemicals Move A protist is surrounded by water, nutrients, and oxygen. Materials just diffuse in and out of the cell. Nitrogen (proteins) Oxygen Gas (O 2 ) Nitrogen Waste Protist Carbon Dioxide (CO 2 ) Water

12. Transportation Needed In a multicellular organism, only the outermost cells can exchange materials with the outside environment. These organisms need a way to get materials in and out of the inner cells. NutrientsOxygen Waste ? CONTENTS

13. Transportation Needed In some simple organisms like this sponge, water with nutrients just flows in and out of the organism.

14. Transportation: “Pipes” In more complicated multicellular organism, there are “pipes” which transport nutrients around the body.

15. Plant Transportation Systems In plants xylem pipes carry water and nutrients up from the roots. Phloem pipes carry food from the leaf down to other cells.

16. Animal Transportation Systems In animals, blood vessels are the pipes that transport food, oxygen, and wastes around the body.

17. Animal Transportation Systems We also call this system the Cardiovascular System. cardio- = heart (the pump) -vascular = vessels (the pipes) CONTENTS

18. Multicellular Organisms: Obtaining Nutrients Multicellular organisms (except plants) need food for energy. They need a system to get food in and broken up for the body to use. Food Waste (unused food) CONTENTS

19. Animals: Obtaining Nutrients Animals have a digestive system which: Takes in food Breaks the food down. Gets the digested food into the blood for transportation to the cells.

20. Because plants make their own food through photosynthesis, they: Do not eat and Do not need a digestive system. Plants do need: Sunlight for energy Water Carbon Dioxide Nutrients

21. Plants: Obtaining Nutrients Plants have organs which help them take in nutrients and to do photosynthesis: Roots – Absorb (take in) water and nitrogen from the soil Leaves – take in carbon dioxide and carry out photosynthesis Take in CO 2 Location of photosynthesis Absorb water Absorb nitrogen CONTENTS

22. Multicellular Organisms: Gas Exchange Multicellular organisms need a system to get oxygen in and carbon dioxide out of the body. OxygenCO 2 CONTENTS

23. Plants: Gas Exchange Plants also need to exchange gases with the atmosphere. For Photosynthesis: CO 2 in O 2 out For Cellular Respiration: O 2 in CO 2 out CO 2 in LEAF O 2 out In Photosynthesis CO 2 in O 2 out

24. Plants: Gas Exchange Plants also need to exchange gases with the atmosphere. For Photosynthesis: CO 2 in O 2 out For Cellular Respiration: O 2 in CO 2 out CO 2 in LEAF O 2 out In Respiration O 2 in CO 2 out CONTENTS

25. Multicellular Organisms: Excretion Multicellular organisms need a system to get poisonous wastes out of the body. Waste CONTENTS

26. Multicellular Organisms: Excretion Removing carbon dioxide (CO 2 ) from the body is also part of excretion. CO 2 out

27. Excretory System We sometimes combine these 2 systems under the heading of the Excretory System. Excretory System Urinary System Respiratory System =+ + CONTENTS

28. Unicellular Organisms: Movement For a protist to move, it simply needs to move its one cell. Protist CONTENTS

29. Multicellular Organisms : Movement A multicellular organism can only move if every cell moves at the same time and in the same direction. A control system is needed for this to happen. CONTENTS

30. Multicellular Organisms: Control A multicellular organism needs to have control systems to coordinate cells. CONTENTS

31. Electrical Control: Nervous System Central Control – Brain and Spinal Cord Nerves to carry messages

32. PLANTS Sorry, no answer here. Discuss this one with your group.

33. Chemical Control: Endocrine System Glands produce chemical hormones. The blood carries these chemical messages. That’s right. The Circulatory System The blood is needed to transport the chemical hormones around the body. CONTENTS

34. PROTECTION Multicellular organisms, like unicellular organisms, need protection. This protection or defense is the combined effort of many systems. Cells work together as a tissue, organs work together in a system, and the systems work together to protect the organism. CONTENTS

35. PROTECTION Your bones and cartilage protect organs. Your bones make up an endoskeleton (inside). Many animals have an exoskeleton (outside). The horseshoe crab’s shell is an exoskeleton.

36. PROTECTION Your muscles aid in protection in allowing you to escape.

37. PROTECTION These 2 systems allow you to sense, react and escape danger.

38. PROTECTION Organisms have skin and often other protective coverings.

39. PROTECTION The circulatory system transports the food and oxygen that you need for dealing with emergencies. Your blood’s ability to clot is protection from both blood loss and harmful pathogens.

40. PROTECTION But the Immune System allows your body to fight off pathogens (outside invaders) that actually enter your body.

41. PROTECTION An army of different types of white blood cells destroy these foreign pathogens and give you immunity (protection) from future “invasions”. CONTENTS

42. PLANT PROTECTION What are some of the organs that plants have to protect themselves? CONTENTS Odor Skunk Cabbage What else can you think of?

43. Reproduction All life can reproduce because every cell has DNA. Most multicellular organisms reproduce sexually by combining an egg with either a sperm or pollen. These two half cells have 1/2 the DNA of each parent and combine to form a whole cell. CONTENTS

44. Plant Reproduction Plants, like animals, reproduce sexually. Flowers produce pollen which fertilize eggs to create seeds. Either wind or insects carry the pollen to another flower.

45. Reproduction But some multicellular organisms can reproduce asexually. Fungi produce spores which unlike eggs, sperm, and pollen contain a complete set of DNA. Only one parent is needed. CONTENTS