Classification and characteristics of living organisms

• What is required for an organism to be classified as living?

  MRS GREN
• What does MRS GREN stand for?

  Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition
• Define movement


  The ability of an organism or part of it to change position or place
• Define respiration


  The chemical reaction that breaks down nutrient molecules in living cells to release energy for metabolism
• Define sensitivity


  The ability to detect or respond to changes in the internal or external environment and to make appropriate responses
• Define growth


  A permanent increase in size and dry mass
• Define reproduction


  The processes that make more of the same kind of organism
• Define excretion


  The removal of the waste products of metabolism and substances in excess requirements
• Define nutrition


  The taking in of materials for energy, growth and development
• How are organisms classified traditionally?

  By the features they share
• What is a species?

  A group of organisms which can reproduce to produce fertile offspring
• What is the sequence of classification?

  Kingdom, Phylum, Class, Order, Family, Genus, Species
• What does the classification of organisms help to show?

  The evolutionary relationships between them
• What else do scientists use to help classify organisms?

  DNA base sequence
• What do DNA chains show?

  The similarity in DNA chains shows how closely the two organisms are related
• What are the 5 kingdoms?


  Animals, plants, fungi, prokaryotes, protists
• What are all living organisms composed of?

  cells
• What do all cells contain?

  cell membrane, cytoplasm, ribosomes, DNA
• What are the main features of animals?

  1. They are multicellular

  2. They contain a nucleus but no cell walls or chloroplasts

  3. They are heterotrophs
• What are vertebrates?


  animals with a backbone and internal skeleton
• What are the 5 vertebrate groups?


  fish, amphibians, reptiles, birds, mammals
• Describe the features of mammals

  1. Fur/hair on the skin

  2. External ears (pinna)

  3. Internal fertilization, giving birth to young

  4. Mammary glands

  5. Breathe through a diaphragm
• Describe the features of reptiles

  1. Dry scaly skin

  2. 4 legs (except snakes)

  3. Internal fertilization, conception from egg

  4. Soft shelled eggs

  5. Breathe through lungs
• Describe the features of fish

  1. Wet scales

  2. Streamlined body shape

  3. External fertilization and soft eggs

  4. Breathe through gills
• Describe the features of amphibians

  1. Smooth, moist skin

  2. External fertilization and soft eggs

  3. Breathe through gills and lungs - live on land and water

  4. Most have 4 legs
• Describe the features of birds

  1. Feathers

  2. Constant body temperature

  3. Hard shelled eggs

  4. Internal fertilization, birth through eggs
• What are invertebrates?


  Animals that lack a backbone
• What standard features do arthropods have?

  1. Exoskeleton

  2. Jointed legs

  3. Segmented body
• What are the 4 athropod groups?

  Myriapods, Insects, Crustaceans, Archnids
• Describe the features of crustaceans

  1. 2 body segments; Cephalothorax and abdomen

  2. 4+ pairs of legs

  3. Mainly aquatic and breathe through gills

  4. 2 pairs of antennae
• Describe the features of arachnids

  1. 2 body segments; Cephalothorax and abdomen

  2. No antennae

  3. 4 pairs of legs

  4. Breathe through book lungs
• Describe the features of myriapods

  1. Segmented body

  2. 1 pair of antennae

  3. 10+ pairs of legs
• Describe the features of insects

  1. 3 body segments; head, thorax and abdomen

  2. 3 pairs jointed legs

  3. 1 pair antennae

  4. 2 pairs of wings
• Describe the main features of plants

  1. They are multicellular

  2. Their cells contain a nucleus, chloroplasts and cellulose cell walls

  3. They all feed by photosynthesis
• Describe ferns


  1. Plants with roots, stems are feathery leaves

  2. Leaves are called fronds

  3. Reproduce by spores
• Describe flowering plants


  1. Plants with roots, stems and leaves

  2. Reproduce sexually by flowers and seeds

  3. Seeds are produced inside the ovary
• Monocotyledons vs dicotyledons

  
• What are the features of fungi?

  Nucleus, non cellulose cell wall, mitochondria, ribosomes and no chlorophyll
• What is the main fungus body called?

  mycelium
• How do fungi feed?

  Do not photosynthesize but feed on dead or decaying material or on live material