The nature and variety of living organisms

Cards (101)

  • What are the 8 life processes?
    movement
    respiration
    sensitivity
    Homeostasis
    growth
    reproduction
    excretion
    nutrition
  • What are the 5 different living organisms?
    1. prokaryote 2. Fungi 3. Plants 4. Animals 5. Protoctists
  • Diffusion is the movement of particles from an area of high concentration to an area of low concentration.
  • Osmosis is the movement of water molecules from an area of high concentration of water molecules to an area of low concentration of water molecules through a partially permeable membrane
  • How is active transport different from osmosis and diffusion?
    • it is an active process
    • it goes against the concentration gradient
  • What is active transport?
    • It is an active process
    • the movement of substances from an area of low concentration to an area of high concentration against the concentration gradient
    • uses energy from respiration
    • involves a protein in the cell membrane
  • What do you find in an animal cell?
    • nucleus
    • cell membrane
    • mitochondria
    • ribosomes
    • cytoplasm
  • What do you find in a plant cell?
    • Cell membrane
    • cytoplasm
    • cell wall
    • vacuole
    • chloroplasts
    • mitochondria
    • nucleus
    • ribosomes
  • Plant features:
    • multicellular
    • have chloroplasts meaning they can photosynthesise
    • Their cells have cell walls made from cellulose
    • they store carbohydrates as sucrose or starch
  • Animal cell features:
    • multicellular
    • cant photosynthesise and don’t have chloroplasts
    • their cells don’t have cell walls
    • have nervous coordination meaning they can respond rapidly to changes in their environment
    • can move from one place to another
    • store carbohydrate in the form of glycogen
  • Fungi
    • Some are single-celled
    • Others have a body called a mycelium, which is made up of hyphae (thread-like structures)
    • Hyphae contain lots of nuclei
    • Can't photosynthesise
    • Cells have cell walls made of chitin
    • Most feed by saprotrophic nutrition - they secrete extracellular enzymes into the area outside their body to dissolve their food, so they can then absorb the nutrients
    • Can store carbohydrate as glycogen
  • Examples of fungi: yeast or Mucor
  • Protoctists:
    • Single Celled and microscopic
    • some have chloroplasts and are similar to plant cells
    • others are more like animal cells
  • protoctists examples:
    chlorella or Amoeba
  • Bacteria:
    • single Celled and microscopic
    • don't have a nucleus
    • have A circular chromosome of DNA
    • some can photosynthesise
    • feed off other organisms, both living and dead
  • Viruses
    • smaller than bacteria, particles rather than cells
    • can only reproduce inside living cells
    • a virus is a parasite- depends on another organism to grow and reproduce
    • infect all types of living organism
    • come in different shapes and sizes
    • dont have a cellular structure - have a protein coat around some genetic material
  • Example of a virus: Influenz, HIV
  • Pathogens are organisms that cause disease. They include some fungi, protoctists and bacteria. Viruses are also pathogens even though they’re not living organisms
  • Cells can be eukaryotic or prokaryotic. eukaryotic cells are complex and include animal and plant cells. Prokaryotic cells are smaller and simpler like bacteria
  • Organelles are tiny structures within cells that you can only see through a microscope
  • Nucleus
    • an organelle that contains the genetic material that controls the cell’s activities. It is surrounded by its own membrane
  • Cell membrane
    • forms the outer surface of the cell and controls the substances that go in and out
  • Cytoplasm
    • a gel like substance where most of the cells chemical reactions happen. It contains enzymes which control these reactions
  • Mitochondria
    • small organelles where most of the reactions for anaerobic respiration take place. respiration transfers energy that the cell needs to work
  • Ribosomes
    • small organelles where proteins are made in the cell
  • Chloroplasts
    • where photosynthesis occurs. Chloroplasts contain a green substance called chlorophyll which is used in photosynthesis
  • Cell wall
    • a rigid structure made of cellulose which surrounds the cell membrane. it supports the cell and strengthens it
  • Vacuole
    • a large organelle that contains cell sap, it helps to support the cell
  • Plant cells

    • Usually have all the organelles
  • Chloroplasts
    Where photosynthesis happens, which makes food for the plant. Contain chlorophyll used in photosynthesis.
  • Cell wall
    A rigid structure made of cellulose, which surrounds the cell membrane. It supports and strengthens the cell.
  • Vacuole
    A large organelle that contains cell sap (a weak solution of sugars and salts). It helps to support the cell.
  • Tissue
    A group of similar cells that work together to carry out a particular function
  • Plant tissues

    • Xylem (for transporting water and mineral salts)
    • Phloem (for transporting sucrose and amino acids)
  • A tissue can contain more than one cell type
  • Organ
    A group of different tissues that work together to perform a function
  • Organs
    • Lungs in mammals
    • Leaves on plants
  • Organ system
    Organs working together to do a different job e.g the digestive system in mammals
  • Most cells are specialised to carry out a certain function so their structures can vary
    e.g red blood cells for carrying oxygen and white blood cells for defending the body against disease
  • Cell differentiation is the process by which a cell changes to become specialised for its job, as cells change they develop different organelles and turn into different types of cells. this allows them to carry out specific functions