Cells for Life

1. Cells of life Grade 8 Science/2011 Term 3 Chapter 4 Compiled by Madre Nortje

2. Cells of life chapter 4 Grade 8 enchantedlearning.com M Nortje 2 tattooednows.blogspot.com Compiled by Madre Nortje

3. M Nortje 3 www. wordle.com

4. What will you know ? • collect information about the microscopic structure of organisms • identify the similarities and differences between plant and animal cells • explain the cell theory and link its development to that of microscopes • draw diagrams of cells and tissues seen under the microscope • explain cell specialisation and give some examples found in plants and animals • make connections between organisation at the cellular, tissue, organand system levels • relate structure and function at different organisational levels. M Nortje 4

5. Cell theory There is no typical cell shape. Cells come in shapes such as cubes (cells lining sweat ducts), spheres (white blood cells in the immune system), columns (cells lining the stomach), rods (some bacteria) and pancakes (cells on the surface of the skin). • All living things are made up of cells. • Cells are the basic units of structure and function in living things. • All cells arise from pre-existing cells. M Nortje 5

6. CELL THEORY M Nortje 6 FIRST TWO PRINCIPLES Matthias Schleiden and Theodor Schwann All living things are made up of cells Cells are the basic units of structure and function in living things. .

7. Third principle Further work by Rudolf Virchow led to 3. All cells arise from pre-existing cells. M Nortje 7

8. History: important dates in the study of cells Year Event 1590 Hans and Zacharias Janssen invented the first microscope. 1665 Robert Hooke saw cells in cork. He first used the name ‘cells’. 1675 Anton van Leeuwenhoek saw bacteria in tooth plaque. 1838 Matthias Schleiden stated that ‘all plants are made of cells’. 1839 Theodor Schwann and Matthias Schleiden proposed the cell theory. 1858 Rudolf Virchow found that cells are able to reproduce. 1860 Ernst Abbe invented the first modern microscope. 1865 Louis Pasteur found that bacteria cause disease. 1931 Max Knoll and Ernst Ruska made the first electron microscope. 1942 Viruses were fi t seen under an electron microscope. 1973 The first successful genetic engineering experiment was performed. 1978 The first baby was born through in-vitro fertilisation (IVF). 1980 to present Further advances were made in genetic engineering and IVF. M Nortje 8

9. Robert hooke1665 microscope M Nortje 9 Used Light from a candle directed by a lens onto the specimen

10. THE MICROSCOPE Van Leeuwenhoek’s microscope One lens mounted in a tiny hole brass plate. Adjusted the position and the focus by turning two screws. First person to observe organisms in water M Nortje 10

11. anton van leeuwehoek M Nortje 11

12. Anton van Leeuwenhoek A Dutch drapper Used lenses to examine pieces of cloth he want to buy Began to use lenses to look at other things Made about 500 microscopes – few still survive today Called microscope – but only Powerful magnifying glasses Could magnify 270 times Could see smaller thing than Hooke could 1675 Observe living things in stagnant water 1683 Observed bacteria under his bacteria – A FIRST M Nortje 12

13. M Nortje 13

14. M Nortje 14 mrruska.pbworks.com

15. Water organisms M Nortje 15

16. M Nortje 16 HOW DOES A CELL LOOK LIKE ? 3 D (Three Dimensional Model of a cell) - picture Parts of a cell is called ORGANELLES

18. Cell is made up of many parts.

19. Not all cells contain all of these parts; it depends on what particular job the cell does.

21. mitochondrion lysosome nuclear membrane nucleic acid nucleus organ organelles M Nortje 19 Vocabulary organism photosynthesis ribosomes stomata system tissue vacuole

22. M Nortje 20 http://puzzlemaker.school.discovery.com Makes crosswords, word search

25. RIBOSOME Little round organelle that makes proteins, which are needed for survival and growth.

26. CHROMOSOMEStrand of nucleic acids in the nucleus of the cell; carries all the genetic information passed from parents to offspring.M Nortje 22

27. CYTOPLASMLiving jelly-like material inside a cell, which is continually moving. NUCLEUSControls the activities of the cell. MITOCHONDRIONThe powerhouse of the cell; supplies energy to the cell. M Nortje 23

29. CHLOROPLAST Green part of plant cells that carries out the chemical reaction called photosynthesis.

31. GOLGI APPARATUS Modifies and packages proteins for transport within the cell or removal from the cell.

34. USE STAIN TO MAKE MORE VISIBLE E.G. THIN CELL MEMBRANES

35. MOST CELLS CONTAIN NUCLEUS AND CYTOPLASMA

36. CELLS VARY vary tremendously in their: SHAPE ACCORDING TO THEIR FUNCTIONS Plant and animal cells

37. DIFFERENCES BETWEEN PLANT AND ANIMAL CELLS M Nortje 28 ANIMAL CELLS Cell membrane Nucleus Cytoplasm PLANT CELLS Cell wall + cell membrane -> cellulose Large cavity -> Vacuole -> watery fluid ->cell sap Cytoplasm May contain starch grains ->nuclues Chloroplasts located in cytoplasma -> green pigment/parts ->exposed to light(leaves) roots - none Chlorophyll used for photosynthesis Cells vary tremendously in their SHAPE

38. The diagram below will help you interpret the photo. ANIMAL CELLS:These cells are from the inside lining of a human cheek. PLANT CELLS:These cells are from the leaf of a plant. M Nortje 29

39. M Nortje 30

40. PLANT AND ANIMAL CELLS M Nortje 31

41. Drawing cells How to draw what you see under the MICROSCOPE • Use a sharp lead pencil (unless you are using a computer drawing package). • Draw only the lines that you see; don’t use shading or colouring. • Each diagram should take up a third to a half of an A4 page. • Record the magnificationnext to the diagram. • State the name of the specimen and the date of the observation. • A written description below the diagram is also often helpful. • When you are viewing many cells of the same type, it is often useful to draw only three or four as a representation of the tissue being observed. M Nortje 32

42. M Nortje 33

43. GAMES SCIENCE 8 – Heinemann DISC Plant CELL Animal CELL M Nortje 34

44. Drawing cells M Nortje 35

45. Preparing wet mount slides M Nortje 36 Images

46. M Nortje 37

47. M Nortje 38

48. Worksheet 4.3Cells crossword Groups of cells of the same type. A group of organs that work together. Jelly-like substance inside cells. General name for any living thing. The organelle containing the pigment that gives plants their green colour. The organelle that makes proteins. The type of reticulum found in cells. Discovered by Robert Hooke. The ‘power house’ of the cell. The control centre of the cell. Pores in the leaf through which gases enter and leave a plant. Organelle that destroys unwanted cells. A magnifier that enable us to see cells and other very small things. Made up mainly of DNA M Nortje 39

49. Cell specialisation (1) M Nortje 40 Most plants and animals are made up of many different types of cells. The cells have different shapes and sizes because they have different jobs to do. Cells are complex things, and they can perform a wide range of tasks including: • taking in nutrients and carrying out chemical reactions • producing waste products

51. Does this list sound familiar? It should! Anything an organismcan do is a result of its cells M Nortje 42 .

53. M Nortje 44 GOBLET CELL Goblet cells are shaped like wine glasses, as the name suggest. They make mucus to lubricate and help and protect our intestines, stomach and windpipe

54. If a cell has to absorb special things that the body needs, for example digested food from the gut, then the cell membrane is foldedto increase its surface area. Cells that are protective, for example skin cells, are flat and fit together to form a complete layer. Cells that line areas where things need to move, for example the fallopian tubes in the female reproductive system or cells lining the respiratory tract, have cilia. Ciliaare hair-like structures that can move. Hair cells from the inner ear carry special stereo cilia that move in response to sound vibrations and send electrical signalsto the brain. Red blood cells have a shape and structure so that they can carry the maximum amount of oxygen. M Nortje 45 Read Only

55. Let’s name the cells? M Nortje 46

56. faculty.college-prep.orgWhite Blood Cells M Nortje 47 sciencequiz.net RED BLOOD CELLS Lots of Nucleus-> packed with oxygen carrying protein haemoglobin. Shaped like biconcave discs – for large surface area for diffusion

58. On the surface of leaves are pores called stomata, which are surrounded by specialised cells called guard cells.

59. The guard cells control the opening and closing of the stomata, allowing gases to go in and out of the plant when necessary.

60. Water leaves a plant through the stomata in the form of water vapour.

61. The guard cells therefore control water loss.M Nortje 48

62. PLANT CELLS HAVE: Nucleus, cytoplasm and a cell membrane, but unlike animal cells, that possess a cell wall and often have large vacuoles. Some contain chloroplasts, which enables them to make their own food M Nortje 49 cimateuagro.org

63. M Nortje 50

64. Special cells on the roots of plants extend into hair-like structures that burrow between soil particles. These cells increase the surface area of the roots. This means that the plant is very efficient at taking up water and nutrients from the soil. Cells in the transport system of plants are modified so that they can provide continuous tubular pathways through roots, stems and leaves. This enables fluids to flow easily to all parts of a plant. M Nortje 51

65. Sci File – Did you know? In the stems of plants are long thin tubes made up of hollow cells, called the xylem and phloem. These tubes are commonly called the veins of the plant. They continue into the leaves and carry water and food to all parts of the plant. M Nortje 52

66. FROM CELL TO ORGANISM M Nortje 53 In any plant or animal there may be millions of different cells. Each cell will carry out its own job. Different types of cells have different structures to enable them to carry out these specific jobs. All the cells working together will make an organism.

67. From cell to organism M Nortje 54

68. TISSUES M Nortje 55 In multi - cellular organisms, similar cells work together in groups called tissues. Tissues are made up of cells that all have a similar appearance and function. An example of an animal tissue is muscle. An animal muscle cell can shorten. One muscle cell by itself is not strong enough to move a bone but many muscle cells together can move the bones of the skeleton. Many muscle cells together are called muscle tissue.

69. TISSUES M Nortje 56 Although there are many types of cells in the human body they are all arranged to form one of the four basic tissue types. THESE ARE: • epithelial tissue (covering tissue), e.g. upper layers of our skin • connective tissue, e.g. bone, blood • muscle tissue • nerve tissue.

70. M Nortje 57 Cells in the bodies of animals vary in size and shape according to their function

73. For example, the stomach is an organ found in some animals.

74. It contains muscle tissue, epithelial tissue lines the outside and the inside, and it also has nerves and blood vessels.

75. Specialised cells within the walls of the stomach produce and secrete chemicals for digestion.

76. The skin, brain, lungs, liver and pancreas are examples of other organs found in animals.M Nortje 59

77. Plant leave – general Organisation of tissue within the leaf M Nortje 60

78. PHOTOSYNTHESIS Plants also have organs, such as roots, leaves, stems and flowers. The leave are important because it is in the leaves that most PHOTOSYNTHESIS takes place M Nortje 61

80. For example, humans possess a circulatory system.

81. The function of the circulatory system is to move materials through the body. It consists of the heart, blood vessels and the blood.systems M Nortje 62

82. Diagram of the skin – many different types of tissue M Nortje 63

83. organisms M Nortje 64 An organism such as a human is made up of many different systems. The systems all work together to help the organism to survive. For example, the muscles cannot work unless they receive oxygen from the blood in the circulatory system

84. Diagram – relationship between cells, tissue, organs and systems M Nortje 65

85. organisms The blood transports oxygen that it collects from the respiratory system. It also supplies nutrients that are used to make energy, and these have been obtained from the digestive system. Some organisms are less complex and have bodies with only a few simple tissues. Other organisms are only one cell, and this cell has to carry out all the functions of our complex tissues, organs and systems. M Nortje 66

86. Word puzzle - cells M Nortje 67 WORD BANK cell membrane cells cell theory cell wall chlorophyll chloroplast chromosomes cilia cytoplasm endoplasmic reticulum Golgi apparatus lysosome mitochondrion

88. M Nortje 69 • The control center of the cell. It is a bit like the brain of the cell. • Small parts of the cell that make the energy for the cell to work. • A thin boundary around the cell that keeps things in cells and lets some things that are needed into the cells. • Little round parts of cells that make chemicals called proteins. Proteins are needed so that we can survive and grow. • Chemicals in the nucleus of the cell that carry all the information we get from our parents. • A boundary around the cell that gives the plant cells a definite shape. These help to give plants shape because plants do not have bones or skeletons like many animals. • Green parts of plant cells that carry out the chemical reaction called photosynthesis. Photosynthesis turns light energy from the Sun into chemical energy (carbohydrates) that animals can use for energy to survive when plants are eaten.

89. Do: Chapter 4 on disc CELLS OF LIFE e TEST M Nortje 70

90. bibliography Coffey,R.Spence, R& Spenceley, M. 2009 Heinemann Queensland Science Project – Science 8 A Contextual Approach. Harcourt Education. Port Melbourne Victoria M Nortje 71