characteristics and classification of living organisms

• 7 characteristics of life:

  1. Move
  2. Respire
  3. Senses
  4. Grow
  5. Reproduce
  6. Excrete
  7. Nutrition
• Species are a group of organisms that can reproduce to produce fertile offspring
• • The Binomial System is an internationally agreed system in which the scientific name of the organism is made up of 2 parts showing the genus & species.
  • Binomial means 2 names.
• Species are almost identical in their anatomy, physiology, and behavior.
• Closely related species are grouped into a genus.
• By classifying organisms, we can know which ones are at risk of extinction & to understand the evolutionary relationship.
• The process of biological classification is called cladistics
• Organisms which share a more recent ancestor have DNA base sequences that are more similar to those who only share a distant ancestor.
• All living organisms have certain features in common such as:

  1. cytoplasm
  2. cell membrane
  3. DNA as a genetic material
• A kingdom is a category of living organisms
• 5 kingdoms:

  1. Animal
  2. Plant
  3. Fungus
  4. Prokaryote
  5. Protoctista
• Animals are multicellular organisms that have no cell wall or chloroplasts.
• Animals are divided into 2 groups:

  1. without a backbone: cnidarians, molluscs, echinoderms, worms, arthropods
  2. with a backbone: fish, mammals, birds, reptiles, amphibians,
• Millipedes & Centipedes: they are made up of a lot of segments:

  Centipedes:

  1. 1 pair of legs on each segment.
  2. fast moving carnivore
  3. 3. powerful jaws & can paralyze their prey.

  Millipedes:

  1. 2 pairs of legs per segment
  2. slow moving herbivores
  3. feed in a leaf litter
• 5 classes of vertebrate:

  1. Fish
  2. Bird
  3. Mammal
  4. Reptiles
  5. Amphibian
• Vertebrates are divided into cold blooded and warm blooded
• Fish, amphibia, and reptiles are cold blooded (poikilothermic)
• mammals and birds are warm blooded (homiothermic)
• the advantage of homeothermy is that the activity of the animal isn't dependent on the temperature of the environment.
• What types of animals are included in the molluscs group?

  Snails, slugs, and squids
• What is the body structure of molluscs?

  Their bodies are soft but not segmented
• How many shells do many molluscs have?

  One or two shells
• What is the function of the muscular foot in molluscs?

  To burrow or move around
• What do molluscs produce for movement?

  Slime or mucus
• What type of skeleton do molluscs have?

  Hydrostatic skeleton
• What respiratory structures do molluscs possess?

  Gills (ctenidia)
• What groups are included in arthropods?

  Crustacea, insects, centipedes, and spiders

  
• Why are arthropods considered the largest group of invertebrates?

  Because they have the highest number of species

  
• What does the term "arthropod" mean?

  Jointed leg
• How are arthropod bodies structured?

  Divided into segments: head, thorax, and abdomen
• What supports the bodies of arthropods?

  A hard skeleton called exoskeletons (cuticle)
• What happens to arthropods when they grow?

  They molt and grow a new exoskeleton
• Where do crustaceans typically live?

  In water
• How do crustaceans breathe?

  By gills
• How many pairs of legs do crustaceans have?

  More than four pairs but less than 20 pairs
• What type of exoskeleton do many crustaceans have?

  A chalky or calcified exoskeleton
• How many pairs of antennae do crustaceans have?

  Two pairs
• What are compound eyes in crustaceans made of?

  Tens or hundreds of separate lenses
• How is the body of crustaceans divided?

  Into cephalothorax and abdomen

  
• What is the largest group of arthropods?

  Insects