1. Cells The Building Blocks of Life

2. How Did the Earth Form? We do not know for certain how the Earth formed. Most scientists agree that the Earth formed about 4.6 billion years ago. That is 4,600,000,000 years ago.

3. Two Theories of How Life on Earth Formed Stanley Miller’s Theory of LifeStanley Miller’s Theory of Life The Volcanic Theory of LifeThe Volcanic Theory of Life

4. Stanley Miller’s Theory of Life This theory states that a mixture of gases and water was struck by lightning and formed a “tar-like” substance that allowed living things to develop. Also known as “Primordial Soup”

5. The Volcanic Theory of Life The Volcanic Theory of Life states that the cooling planet had lots of volcanoes putting gases into the air. These gases condensed into rain that formed oceans. Single cell organisms evolved into plant life then animal life.

6. How did Cells Form? Several Theories of How Cells Formed: –Cells arose in shallow pools containing “soup” of chemicals. These chemicals become combined and formed cells. –Cells formed in beds of clay that allowed substances (chemicals) to be contained and produce living things – cells. –Meteors and asteroids carried water, containing life (cells) to the Earth.

7. Which Cell Theory Is True? We still do not know for sure how cells formed.

8. Spontaneous Generation? The Theory of Spontaneous Generation states that life could arise from non-living matter.The Theory of Spontaneous Generation states that life could arise from non-living matter. –This theory was disproved in 1668 by Francesco Redi who used raw meat for his experiments.

9. Francesco Redi

10. Redi’s Experiment

11. Producers and Consumers A producer is any organism that makes it’s own food. –Example: green plants A consumer is any organism that can not produce it’s own food. –Consumers are dependent on other organisms to survive. –Example: Man

12. How Do Producers Make Food? PhotosynthesisPhotosynthesis: the process by which green plants convert sunlight into food. –As a waste product, oxygen is released. –At some point in history, early cells evolved and became able to perform photosynthesis. This is important because this allowed an oxygen atmosphere to form and eventually allows for animal life to evolve.

15. Characteristics of Living Things All living things share characteristics, they: –Are made of cells –Are able to move –Perform complex chemical activities –Are able to grow and develop –Are able to respond to their environment –Are able to reproduce

16. What is a Cell? The cell is the basic building block of all living things.The cell is the basic building block of all living things. –The first cells on Earth are thought to have evolved ~3.5 billion years ago. –These cells could not produce their own food.

17. All living things are made of cells Plant CellsAnimal Cells

19. All living things are able to move

20. All living things perform complex chemical activities “building up and breaking down” MetabolismMetabolism is the sum total of all the chemical reactions that occur in a living thing. –In humans these chemical reactions are ingestion, digestion, respiration, and excretion.

21. Nutrition NutritionNutrition is the process of obtaining food and breaking it down into a useable form for cell absorption.

22. Ingestion Ingestion is taking in food to process.Ingestion is taking in food to process.

23. Digestion Digestion is the process of breaking down food into simpler substances.

24. Transport Nutrients and other necessary materials are delivered to all the cells of the organism; wastes are carried away.

25. Respiration RespirationRespiration is the process of taking in oxygen and using it to produce energy.

26. Excretion ExcretionExcretion is the process of getting rid of waste material.

27. Regulation RegulationRegulation is the control and coordination of all life functions. It also involves the response of an organism to changes in the environment.

28. All living things are able to grow and develop Life span is the maximum length of time that an organism is expected to live.

29. All living things are able to respond to their environment stimulusA stimulus is something that comes from outside the organism or from within the organism that triggers a reaction. Examples: cold breeze stomach growl responseA response is the reaction that occurs as a result of the stimulus. Examples: goose bumps eat food

30. All living things are able to reproduce “Like produces like” Sexual reproduction: –Requires two parents –Results in offspring that show variations Asexual reproduction: –Requires one parent –Results in identical offspring with no variations blueprint Both forms of reproduction give a chemical “blueprint” to the next generation.

31. Cellular Reproduction

32. Egg and Sperm Cells - Fertilization

33. Meiosis - Sexual Reproduction Result is daughter cells with half the chromosomes

34. Mitosis – Asexual Reproduction Result is two identical cells

35. What are the Needs of Living Things? In order to survive all living things need: –Energy –Food –Water –Oxygen –Living space –To maintain a proper temperature

36. How Do Living Things Maintain Proper Temperature Homeostasis is the ability of an organism to keep the conditions inside the body the same even though external environmental conditions change.Homeostasis is the ability of an organism to keep the conditions inside the body the same even though external environmental conditions change. Warm blooded animals maintain a constant body temperature at all times.Warm blooded animals maintain a constant body temperature at all times. –Examples are man and mammals Cold blooded animals have body temperatures that change with the environment.Cold blooded animals have body temperatures that change with the environment. –Examples are fish and reptiles

37. What Makes Up All Living Things? “The Chemistry Of Life” All living things are made of elements and compounds.

38. What is an Element? An element is a pure substance that can not be broken down into any simpler substances. –Only 90 natural elements exist on earth. –Only 11 elements are common in living things. –4 elements (carbon, nitrogen, oxygen and hydrogen) make up 96% of the weight of the human body.

40. What is a Compound? A compound is formed when 2 or more elements join together chemically. –Examples are: water H 2 O, and sugar C 6 H 12 O 6

41. A water molecule is an example of a compound

42. Cell Theory The current cell theory states that: –All living things are made of cells. –Cells are the basic unit of structure and function in living things. –Living cells only come from other living cells.

43. What Are Cells Made Of? Organelles, or “tiny organs”, are the structures that make up a cell.Organelles, or “tiny organs”, are the structures that make up a cell. Organelles were discovered by Robert Hooke in 1665 while looking at cork cells.Organelles were discovered by Robert Hooke in 1665 while looking at cork cells.

44. How Do Cells Function? Each of the organelles in a cell has a defined function. There are many organelles that make up a cell. –These include the cell wall, cell membrane, nucleus, cytoplasm, endoplasmic reticulum, ribosomes, lysosomes, mitochondria, vacuoles, chloroplasts. All organelles working together create the cells structure.

45. Plant Cells vs Animal Cells Animal Cell Plant Cell

47. Cell Organelles – Cell Wall cell wallsupport protectionThe cell wall provides support and protection for the cell. cell wallThe cell wall is rigid. Cell wallsCell walls are only found in plant cells.

48. Cell Wall – only in plants

49. Cell Organelles – Cell Membrane The cell membrane is the “doorway” of the cell. Cell membranes control the movement of materials into and out of the cell. –Pores are the openings in the cell membrane. Cell membranes provide support and protection. –In plant cells the cell membrane is found just inside the cell wall. –In animal cells the cell membrane is the outermost organelle.

51. Cell Membrane

52. Cell Organelles - Nucleus The nucleus is the “control center”, or “brain” of the cell which controls all activities in the cell.The nucleus is the “control center”, or “brain” of the cell which controls all activities in the cell. The nucleus has three parts:The nucleus has three parts: –Nuclear membrane –Chromosomes –Nucleolus

53. Cell Organelles - Nucleus nuclear membraneThe nuclear membrane controls the movement of materials into and out of the nucleus. chromosomesThe chromosomes direct the activities within the cell and also pass on genetic traits to the next generation. nucleolusThe nucleolus, or “little nucleus” is the site of ribosome production.

54. Cell Organelles - Cytoplasm Cytoplasm is the clear, thick jelly- like substance that contains all the organelles.Cytoplasm is the clear, thick jelly- like substance that contains all the organelles.

55. Cell Organelles – Endoplasmic Reticulum The endoplasmic reticulum, or ER, is the tubular transportation system throughout the cell.The endoplasmic reticulum, or ER, is the tubular transportation system throughout the cell.

56. Endoplasmic Reticulum Smooth and Rough

57. Cell Organelles - Ribosomes Ribosomesprotein factoriesRibosomes are the protein factories of the cell. ribosomesMost ribosomes are found attached to the outside of the endoplasmic reticulum. –This location helps the cell with efficiency of production and transport.

58. Ribosomes

59. Cell Organelles - Lysosomes Lysosomes“clean up crew”Lysosomes are the “clean up crew” of the cell. LysosomesLysosomes are involved in the digestive process of the cell. –Enzymes break down large food into smaller bits for the mitochondria to use. –Lysosomes –Lysosomes are not common in plant cells.

61. Cell Organelles - Mitochondria MitochondriapowerhouseMitochondria are the “powerhouse” of the cell and supply most of the energy for the cell.

62. Cell Organelles - Vacuoles VacuolesVacuoles are the “storage tanks” of the cell. VacuolesVacuoles can store food, water, or waste. vacuoles –In plant cells vacuoles are common. Usually one large vacuole per cell. vacuoles –In animal cells vacuoles are not common. Usually several small vacuoles per cell.

64. Cell Organelles - Chloroplasts Chloroplasts“energy producers”Chloroplasts are the “energy producers” of plant cells. Chloroplastsonly found in plant cellsChloroplasts are only found in plant cells. ChloroplastschlorophyllChloroplasts contain green chlorophyll that captures energy from the sun.

65. How Do Materials Move Into and Out Of The Cell? Materials enter and leave a cell by one of three methods: –Diffusion –Osmosis –Active Transport

66. What is Diffusion? DiffusionDiffusion is the process by which molecules of a substance move from areas of high concentration to areas of low concentration. selectively permeable. –The cell membrane is selectively permeable.

68. Diffusion from high concentration to low concentration

69. What is Osmosis? OsmosisOsmosis is the diffusion of water into or out of a cell. do not require energyBoth diffusion and osmosis do not require the cell to use up it’s energy.

70. What is Active Transport? Active transport carriesActive transport is the process by which the cell “carries” a substance in or out. This requires the cell to use its energy. When does active transport occur? –If the cell membrane is not permeable for the substance. –If the concentration levels inside and outside the cell are not different enough.

71. What Is Cell Specialization? In multicellular organisms, cells not only complete its own life activities, but also performs a function that contributes to the life of the organism.In multicellular organisms, cells not only complete its own life activities, but also performs a function that contributes to the life of the organism. Within multicellular organisms there is division of labor or specialization.Within multicellular organisms there is division of labor or specialization. –The work of keeping the organism alive is divided up among different parts of the organism.

72. Levels of Specialization Cells combine to form Tissues combine to form Organs combine to form Organ systems combine to form Organism

73. More Specialization Students combine to form Classes combine to form Grades combine to form Schools combine to form District

74. Taxonomy TaxonomyTaxonomy is the science of naming, describing and classifying organisms. –Living organisms are organized into categories based on characteristics. –The classification system of living organisms is arranged from a large category of kingdom to smaller specific category of species

75. 5 Kingdoms Monera: one-celled, no nucleus Protist: one-celled with nucleus Fungus: many-celled, heterotrophic, lacks chlorophyll Plant: many-celled, autotrophic, contains chlorophyll Animal: many-celled, heterotrophic

76. What is a Virus? A virus is different form other living organisms because it lacks cellular organization. Herpes simplex virus