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Igcse biology edexcel 1.1 1.3

Chemistry/Biology Teacher en Saint Nicholas School
16 de Sep de 2014
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Igcse biology edexcel 1.1 1.3

  1. IT’S ALIVE !!!! 1.1 Understand that living organisms share the following characteristics: they require nutrition; they respire; they excrete their waste; they respond to their surroundings; they move; they control their internal conditions; they reproduce; they grow and develop. M Movement All living things move, even plants R Respiration Getting energy from food S Sensitivity Detecting changes in the surroundings G Growth All living things grow and develop R Reproduction Making more living things of the same type (species). E Excretion Getting rid of waste N Nutrition Taking in and using food and other nutrients In addition, all living organisms contain nucleic acids (DNA/RNA) and have the ability to control their internal conditions (homeostasis). Finally, all living organisms can die.
  2. ALIVE OR NOT ALIVE!! ALIVE OR NOT ALIVE 1.1 Understand that living organisms share the following characteristics: they require nutrition; they respire; they excrete their waste; they respond to their surroundings; they move; they control their internal conditions; they reproduce; they grow and develop.
  3. GROUPS OF LIVING ORGANISMS 1.2 describe the common features shared by organisms within the following main groups: plants, animals, fungi, bacteria, protoctists and viruses, and for each group describe examples and their features as follows (details of life cycle and economic importance are not required)
  4. PLANTS Plants: These are multicellular organisms; their cells contain chloroplasts and are able to carry out photosynthesis; their cells have cellulose cell walls; they store carbohydrates as starch or sucrose Plants all have the following in common: 1) Multicellular organisms (made of lots of cells) 2) Cells contain chloroplasts and are able to carry out photosynthesis. Photosynthesis takes simple inorganic molecules and turns them into simple sugar (glucose). Glucose can be turned into complex organic molecules such as carbohydrates.
  5. PLANTS Plants: These are multicellular organisms; their cells contain chloroplasts and are able to carry out photosynthesis; their cells have cellulose cell walls; they store carbohydrates as starch or sucrose 3) Cells have cellulose cell walls (cellulose is a carbohydrate)
  6. PLANTS Plants: These are multicellular organisms; their cells contain chloroplasts and are able to carry out photosynthesis; their cells have cellulose cell walls; they store carbohydrates as starch or sucrose 4) They store carbohydrates as starch. Carbohydrates are polysaccharides (many sugars/glucose linked together) or sucrose. Sucrose is a disaccharide (two sugars linked together).
  7. Examples you need to know: 1) flowering plants, such as a cereals A) Maize PLANTS Examples include flowering plants, such as a cereal (for example maize), and a herbaceous legume (for example peas or beans) B) Wheat
  8. PLANTS Examples include flowering plants, such as a cereal (for example maize), and a herbaceous legume (for example peas or beans) 2) Herbaceous legume (e.g. peas or beans). Root nodules
  9. ANIMALS Animals: These are multicellular organisms; their cells do not contain chloroplasts and are not able to carry out photosynthesis; they have no cell walls; they usually have nervous coordination and are able to move from one place to another; they often store carbohydrate as glycogen 1) Animals include: sponges, molluscs, worms, starfish, insects, crustaceans, fish, amphibians, reptiles, birds, mammals Animals without a backbone (vertebral column) are invertebrates. Animals with a vertebral column are called vertebrates. 2) Animals are Multicellular organisms
  10. ANIMALS Animals: These are multicellular organisms; their cells do not contain chloroplasts and are not able to carry out photosynthesis; they have no cell walls; they usually have nervous coordination and are able to move from one place to another; they often store carbohydrate as glycogen 3) They have a nervous system 4) They often store carbohydrate as glycogen in the liver and muscles.
  11. ANIMALS Animals: These are multicellular organisms; their cells do not contain chloroplasts and are not able to carry out photosynthesis; they have no cell walls; they usually have nervous coordination and are able to move from one place to another; they often store carbohydrate as glycogen 5) Animal cells do not contain chloroplasts and are not able to carry out photosynthesis 6) Animal cells have no cell walls
  12. ANIMALS Animals: These are multicellular organisms; their cells do not contain chloroplasts and are not able to carry out photosynthesis; they have no cell walls; they usually have nervous coordination and are able to move from one place to another; they often store carbohydrate as glycogen
  13. ANIMALS Examples include mammals (for example humans) and insects (for example housefly and mosquito) Examples you need to know: 1) Human (mammal)
  14. 2) Insects Examples include mammals (for example humans) and insects (for example housefly and mosquito) a) Housefly ANIMALS Why the housefly? - They regurgitate stomach enzymes onto their food - but also because other flies are interesting A) Tsetse fly B) Screw fly C) Drosophila
  15. ANIMALS Examples include mammals (for example humans) and insects (for example housefly and mosquito) Lastly….. the use of flies ended the belief in the spontaneous generation of life
  16. Examples include mammals (for example humans) and insects (for example housefly and mosquito) b) Mosquito ANIMALS Video Bite So why the Mosquito? (it is really just another fly!) - Complex life cycle - Can be a vector for malaria, yellow fever, abrovirus - Control measures have damaged ecosystems
  17. FUNGI Fungi: These are organisms that are not able to carry out photosynthesis; their body is usually organised into a mycelium made from thread-like structures called hyphae, which contain many nuclei; some examples are single-celled; their cells have walls made of chitin; they feed by extracellular secretion of digestive enzymes onto food material and absorption of the organic products; this is known as saprotrophic nutrition; they may store carbohydrate as glycogen Characteristics of Fungi: 1) They feed by saprophytic nutrition (feeds on dead organic material & digestion takes place outside the organism. 2) Fungi feed by excreting extracellular secretions of digestive enzymes onto food and absorbing the digested products. 3) Cells are joined together to form threads, called hyphae. Hyphae contain many nuclei, because they are made from many cells. 4) Hyphae join together to make a network of threads called mycelium
  18. FUNGI ARE NOT PLANTS 5) Cells do not contain chloroplasts and are not able to carry out photosynthesis 6) Cell walls are made from a protein called chitin (not cellulose) 7) They store carbohydrates as glycogen (not starch) FUNGI Fungi: These are organisms that are not able to carry out photosynthesis; their body is usually organised into a mycelium made from thread-like structures called hyphae, which contain many nuclei; some examples are single-celled; their cells have walls made of chitin; they feed by extracellular secretion of digestive enzymes onto food material and absorption of the organic products; this is known as saprotrophic nutrition; they may store carbohydrate as glycogen
  19. FUNGI Fungi Examples include Mucor , which has the typical fungal hyphal structure, and yeast, which is single-celled Examples you must know: 1) Mucor (bread mold) Why do you need to know about Mucor? - Easy to experiment on in the lab (temperature, moisture) - Mucor must use energy to absorb nutrients in it’s hyphae - Was used to produce penicillin, the first antibiotic.
  20. FUNGI Fungi Examples include Mucor , which has the typical fungal hyphal structure, and yeast, which is single-celled 2) Yeast (single celled fungi) Why do you need to know about Yeast? - Easy to experiment on in the lab (temperature & sugar concentration) - Yeast is used in the production of beer & bread
  21. BACTERIA Bacteria: These are microscopic single-celled organisms; they have a cell wall, cell membrane, cytoplasm and plasmids; they lack a nucleus but contain a circular chromosome of DNA; some bacteria can carry out photosynthesis but most feed off other living or dead organisms Bacteria Characteristics: 1) Made from single cells 2) Cells do not contain a nucleus. Bacteria cells have a small piece of circular DNA instead of a nucleus (a bacterial chromosome/nucleoid). 2) Bacteria also have DNA in the form of circular plasmids 3) most gain their nutrients by saprophytic nutrition (feed off dead organisms) or by parasitic nutrition (feed off living organisms). Some bacteria can carry out photosynthesis. You need to know their structure: TED
  22. BACTERIA Bacteria: These are microscopic single-celled organisms; they have a cell wall, cell membrane, cytoplasm and plasmids; they lack a nucleus but contain a circular chromosome of DNA; some bacteria can carry out photosynthesis but most feed off other living or dead organisms Some pretty pictures of bacteria
  23. BACTERIA Examples include Lactobacillus bulgaricus , a rod-shaped bacterium used in the production of yoghurt from milk, and Pneumococcus , a spherical bacterium that acts as the pathogen causing pneumonia Example you need to know: 1) Lactobacillus bulgaricus - Used to make yogurt - Produces lactic acid (excretes) - Rod shaped - Not dangerous to humans Why Lactobacillus bulgaricus? - It is used in how human food production - lowers the pH of milk to inhibit harmful to human bacterial growth
  24. Examples include Lactobacillus bulgaricus , a rod-shaped bacterium used in the production of yoghurt from milk, and Pneumococcus , a spherical bacterium 2) Pneumococcus BACTERIA that acts as the pathogen causing pneumonia - pathogen causes pneumonia (inflammation of one or both lungs) - killed with antibiotics - spherical bacteria shape Why Pneumococcus? - reduces surface area of alveoli - use of antibiotics in treatment can lead to resistant strains
  25. PROTOCTISTS Protoctists: These are microscopic single-celled organisms. When you don’t fit in scientists drop you into the Protoctists group! Protoctists Characteristics: - most are single celled (exception is seaweeds) - Some have animal-like features - protozoa - Some have plant-like features – algae swim
  26. PROTOCTISTS Some, like Amoeba, that live in pond water, have features like an animal cell, while others, like Chlorella, have chloroplasts and are more like plants. A pathogenic example is Plasmodium , responsible for causing malaria Examples you need to know: 1) Amoeba - protozoa - live in pond water - Pathogen amoeba can cause Amoebic dysentery (kills 70,000 people every year) Why Amoeba? - Highlights the need for clean drinking water supplies - Uses amoebiasis to feed (similair to phagocytosis) eating
  27. Some, like Amoeba, that live in pond water, have features like an animal cell, while others, like Chlorella, have chloroplasts and are more like plants. A 2) Chlorella PROTOCTISTS pathogenic example is Plasmodium , responsible for causing malaria - ‘more’ like plants than animals - have chloroplasts Why Chlorlla? - both animal and plant characteristics - Possible food source (1940’s solution to world hunger) view
  28. 3) Plasmodium - Protozoa - pathogen that causes malaria - uses a mosquito as a vector (transfer) - not killed by antibiotics Why plasmodium? - it is the greatest pathogen killer! TED PROTOCTISTS Some, like Amoeba, that live in pond water, have features like an animal cell, while others, like Chlorella, have chloroplasts and are more like plants. A pathogenic example is Plasmodium , responsible for causing malaria
  29. VIRUS Viruses: These are small particles, smaller than bacteria; they are parasitic and can reproduce only inside living cells; they infect every type of living organism. They have a wide variety of shapes and sizes; they have no cellular structure but have a protein coat and contain one type of nucleic acid, either DNA or RNA Viruses Characteristics: 1) Much smaller than bacteria. 1) They are not made from cells (no cellular structures) 3) Totally parasitic and reproduce inside host cells. 3) They infect every type of living cell 3) Have either DNA or RNA as genetic material 3) Have a protein coat
  30. VIRUS Viruses: These are small particles, smaller than bacteria; they are parasitic and can reproduce only inside living cells; they infect every type of living organism. They have a wide variety of shapes and sizes; they have no cellular structure but have a protein coat and contain one type of nucleic acid, either DNA or RNA You just have to recognize a virus, but there are several shapes
  31. VIRUS Viruses: These are small particles, smaller than bacteria; they are parasitic and can reproduce only inside living cells; they infect every type of living organism. They have a wide variety of shapes and sizes; they have no cellular structure but have a protein coat and contain one type of nucleic acid, either DNA or RNA REVIEW FROM YEAR 8
  32. VIRUS Examples include the tobacco mosaic virus that causes discolouring of the leaves of tobacco plants by preventing the formation of chloroplasts, the influenza virus that causes gfluc and the HIV virus that causes AIDS Examples you need to know: 1) Tobacco Mosaic Virus - infects crop plant and prevents formation of chloroplasts - symptoms are discoloration of leaves Why Tobacco Mosaic Virus? - first identification of a virus as a pathogen (1898, Martinus W. Beijerinck) - Genetic engineering
  33. VIRUS Examples include the tobacco mosaic virus that causes discolouring of the leaves of tobacco plants by preventing the formation of chloroplasts, the influenza virus that causes gfluc and the HIV virus that causes AIDS 2) Influenza Virus - Viral pathogen causes the flu - Transmitted through air/ contact Why the Flu? - Pandemics (spanish flu) - Mutations leading to new strains - Vaccinations vaccine Flu History
  34. Just thought you would like to know.
  35. 3) HIV (human immunodeficiency virus) - Pathogen causes AIDS (acquired immunodeficiency syndrome) - Virus attacks white blood cells (immune system) - Host killed by secondary disease - Transmitted by blood to blood contact Why HIV? - Immune system - Mutations VIRUS Examples include the tobacco mosaic virus that causes discolouring of the leaves of tobacco plants by preventing the formation of chloroplasts, the influenza virus that causes gfluc and the HIV virus that causes AIDS
  36. PATHOGEN 1.3 recall the term gpathogenc and know that pathogens may be fungi, bacteria, protoctists or viruses. Pathogen: An agent that causes infection or disease, especially a microorganism, such as a bacterium or protozoan, or a virus.
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