Section 1: The Nature and Variety of Organisms

• MRS C GREN


  Movement

  Respiration

  Sensitivity

  Control

  Growth

  Reproduction

  Excretion

  Nutrition
• Excretion


  Organisms getting rid of waste products of metabolism
• Metabolism


  Chemical processes that occur within a living organism to maintain life
• Metabolic Waste

  Product leftover from chemical reactions in metabolism that need to be removed
• Egestion


  Removal of feces/solid waste from your body
• Respiratory

  Job : Release chemical energy from glucose in the cells

  Organ : Lungs
• Circulatory

  Job : Carry substances around the body in blood

  Organ : Heart
• Excretory

  Job : Removes waste from the body

  Organ : Kidneys, Bladder
• Digestive

  Job : Breaks down food

  Organ : Stomach, intestines
• Reproductive

  Job : Producing new living beings

  Organ : Testes, uterus, ovary
• Nervous system

  Job : Send messages around the body

  Organ : Skin,nerves,brain
• Skeletal system

  Job : Provides support and movement

  Organ : Skeleton and Muscles
• Why urine and faeces not direct products from metabolic waste?

  Urine and feces are not direct products of metabolic waste because they undergo additional processing in the body before being excreted.

  Faeces is an indirect product of metabolic waste

  There are other form of excretion (breathing/sweating)
• Eukaryotic organisms - Have a nucleus containing DNA

  • Animal -> mammals
  • Plants -> grass
  • Fungi -> yeast
  • Protoctists -> plasmodium -> malaria
• Prokaryotes - dont have a nucleus

  Bacteria -> cholera
• TMV -> Tobacco Mosaic Virus -> prevent formation of chloroplast

  Viruses are non-living; much smaller than bacteria

  Parasites -> live & reproduce in a host, causing harm

  Pathogen - organism that causes disease
• Multi-cellular

  Has a chloroplast

  Cell wall - cellulose

  Store sugar - Starch

  
  

  It is a plant
• Animals

  Multi-cellular

  No cell wall

  Carbohydrate stored as glycogen

  Nervous co-ordination
• Fungi = Unicellular or multicellular

  Cell wall - Chitin

  Fibre network - mycelium of hyphae

  Saprotrophic ~ glucose = glycogen

  
  

  Its a pathogen because it causes athletes foot
• Protoctists= Mostly single-celled

  (in exam write mostly single celled but some of them

  are multi-cellular)

  
  

  Its a pathogen because it forms plasmodium which causes malaria
• 3 sub cellular parts plants have but animals dont

  Vacuole (permanent)

  Chloroplast

  Cell wall
• Cell

  Basic unit of life
• Nucleus 🪴🐄

  
  

  Function - Controls all activities in a cell
• Mitochondria 🪴🐄

  Function - Respiration ; releases energy for cell use
• Ribosome 🪴🐄

  Function - Site of protein synthesis
• Cell membrane🪴🐄

  Function - Controls what goes in and out of a cell
• Cytoplasm🪴 🐄

  Function - Most chemical reactions take place
• Cell Wall 🪴

  Function - Strengthens cell , provide support
• Permanent Vacuole🪴

  Function - Stores sap ; keep plants rigid by providing structural support
• Chloroplast 🪴

  Function - Absorb light for photosynthesis
• Chlorophyll🪴

  Function - Helps plants go through photosynthesis by capturing energy from light
• Why do we use iodine when I am using a microscope?

  Iodine acts as a stain to see different organelles in a cell (plants)

  Methyline blue -> used for animal cells while looking into a microscope
• Eyepiece Lens: Part of a microscope you look into
• Magnification: How big an object is magnified compared to its original size
• Objective Lens: Part of microscope that is closest to the specimen
• Stain : An ink that is used on plant cells in a microscope to make it easier to see
• Magnification (M) = size of image (I) /size of real object (A)
• Beneficial bacteria - lactobacillus in milk

  Harmful bacteria - Pneumococcus - Pneumonia
• Fungi

  Unicellular - yeast

  Multicellular - mold
• How do fungi feed?

  Saprotrophic nutrition. They feed of dead matter and secrete enzymes to break sugar into soluble substance.