Biology - Unit 1: Characteristics and classification of living organisms

• Dychotomous key


  help identify living things includes a series of statements or questions
• Monocotyledon


  long narrow leaves with parallel veins the parts of the flower are in multiples of 3have 1 cotyledon in each seed
• Example of dicotyledon

  the oak tree, magnolia plant
• cotyledon


  A "seed leaf" which develops as a part of the seed. It provides nutrients to the developing seedling and eventually becomes the first leaf of the plant.
• Dicotyledon


  leaves are broad with a network of branching veins the male part know as stamens are in multiple of 4 or 5 in each flowerhave 2 cotyledons in each seed
• two main types of flowering plants

  Monocotyledon and dicotyledon
• roots

  found below ground do not contain chlorophyll anchor the plantabsorb water and mineral ions from the soil
• the stem


  allows transport of water from the soil to the leaves and food from the leaves to other parts following photosynthesis
• pollenation


  transfer of pollen from the anther to the stigma of a plant
• apical bud


  the part where stem grows new leaves
• shoot


  part of the plant above ground consisting of the stem, leaves, buds and flowers
• flowering plants


  have true stems, roots and leaves reproduce through flowers which provide seeds in the flower's ovary
• rhizome


  a horizontal, underground stem that produces new leaves, shoots, and rootsmany ferns grow from this
• ferns


  a group of plants whose leaves have a waxy layer to help reduce water lost have strong stems, roots and compound leavesdo not produce seeds; microscopic spores cling to the under side of the leaves and are carried by the wind to form new plants
• chlorophyll


  A green pigment found in the chloroplasts of plants, algae, and some bacteria that absorbs light energy used to carry out photosynthesis
• Chloroplast


  a cell organelle that contains the green pigment chlorophyll which absorbs light for photosynthesis
• ferns and flowering plants

  multicellulargreen in colour cells have cell walls made of cellulose photosynthesisehave a tube system to carry water and minerals
• examples of arachnids

  spiders, scorpions, ticks, mites
• spinneretes


  attach to silk glands (found in arachnids)
• arachnids

  bodies divide into 2 parts, the cephalothorax and abdomen have 4 pairs of legs have several pairs of simple eyes can paralyze prey with poison fangscan weave silken webs
• example of insects

  beetles, flies, cockroaches, butterflies
• spiracles


  breathing tubes of insects located on abdomen
• insects

  bodies divided into 3 parts: head, thorax and abdomen thorax has 3 pairs of legs and sometimes 2 pairs of wings 1 pair of antenna compound eyes breathe through holes in the sides of the thorax and abdomen covered by waterproof cuticle to stop them from losing water
• example of myriapods

  centipedes and millipedes
• myriapods


  long bodies made up of many segments with either 1 pair of legs or 2 pairs of legs on each segment
• examples of crustaceans

  lobster, crab, shrimp
• crustaceans


  body divided into cephalothorax (head-thorax) and abdomen hard, chalky exoskeleton 2 pair of antennae2 pair compound eyes between 5 and 20 pairs of legs breath using gills nearly all live in water
• example of arthropods

  insects, crustaceans, arachnids (crabs, spiders, beetle), myriapods
• arthropods

  largest group in the animal kingdom segmented bodyhas an exoskeletonhas jointed legs
• invertebrates

  do not have a vertebral column or backbone
• fish

  - most live in water permanently- have fins for swimming and balance - have a lateral line for detecting pressure- breathe dissolved oxygen using gills - skin is covered with scales
• examples of amphibians

  frogs, toads, salamanders
• amphibians


  - vertebrates with smooth moist skin- live on land but breed in the water - fertilization is external- during development the young have gills for breathing - as adults have lungs for breathing but can breathe through their skin when in water
• examples of reptiles

  Crocodiles, lizards, snakes and turtles
• reptiles

  - dry, fixed scales on skin to cut down on water loss- lay eggs with rubbery shells on land which are waterproof to stop them from drying out - have lungs to breathe air- fertilization is internal
• Homeothermic (endothermic)


  Warm-blooded; the ability to maintain one's own body temperature.
• birds


  - skin covered in feathers- have 2 legs and 2 wings instead of forelimbs - some can fly others cannot (penguins and ostriches)- fertilization is internal and development is external- lay eggs with hard shells on land - have a beak- homeothermic/endothermic
• mammals

  - have hair/fur on skin - have a placenta - fertilization is internal and development is external- the young develop in a womb and are born well developed - the young feed on milk from mammary glands- use lungs for breathing - homeothermic/endothermic
• the 5 main groups of vertebrates

  mammals, birds, reptiles, amphibians, fish
• vertebrates


  animals that have a backbone or vertebral column