biology

• CSEC® Biology examination


  Consists of two papers: Paper 01 (multiple choice) and Paper 02 (structured and extended response questions)
• Paper 01


  • 60 multiple choice questions, 1 mark each, 4 choices of answer with 1 correct

  
• Paper 02


  • Section A: 3 compulsory structured questions, Section B: 3 compulsory extended response questions
• The marks allocated for the different parts of each question are clearly given
• A total of 100 marks is available for Paper 02 and the time allowed is 150 minutes
• Successful revision tips


  • Begin revision early
  • Plan a revision timetable
  • Understand topics before learning
  • Revise every topic in the syllabus
  • Revise in a quiet location
  • Sit up to revise
  • Use past exam papers for practice
• A variety of different methods can be used to learn the work, choose the ones that work best
• Nutrition


  The process by which living organisms obtain or make food
• Heterotrophs


  Animals that take in ready-made food
• Autotrophs


  Plants that make their own food
• Respiration


  The process by which energy is released from food by all living cells
• Aerobic respiration


  Requires oxygen and takes place in most cells
• Anaerobic respiration


  Takes place without oxygen in certain cells
• Excretion


  The process by which waste and harmful substances, produced by the body's metabolism, are removed from the body
• Movement


  A change in the position of a whole organism or of parts of an organism
• Irritability (sensitivity)


  The ability of organisms to detect and respond to changes in their environment or within themselves
• Growth


  A permanent increase in the size and complexity of an organism
• Reproduction


  The process by which living organisms generate new individuals of the same kind as themselves
• Asexual reproduction


  Requires only one parent
• Sexual reproduction


  Requires two parents
• Classification of living organisms

  • Based on similarities and differences between living organisms
  • Can be done based on visible characteristics
  • Can also use internal structures, developmental patterns, life cycles and electron microscopic techniques
  • Modern classification uses molecular structure of DNA to assist in grouping organisms

  
• Species


  A group of organisms of common ancestry that closely resemble each other and are normally capable of interbreeding to produce fertile offspring
• Levels of classification


  • Species
  • Genera
  • Families
  • Orders
  • Classes
  • Phyla
  • Kingdoms
• Five kingdoms in modern classification

  • Prokaryotae (bacteria and blue-green algae)
  • Protoctista (protozoa and algae)
  • Fungi
  • Plantae (plants)
  • Animalia (animals)
• Viruses are not included in the five kingdom classification
• Prokaryotae


  • Unicellular organisms
  • Cells have a cell wall
  • Cells lack a true nucleus, the DNA is free in the cell
  • Cells lack other membrane-bound organelles, e.g. mitochondria, chloroplasts
  • Most feed by absorbing food
• Protoctista


  • Most are unicellular, some are simple multicellular organisms that lack any complex development of tissues and organs
  • Cells have a true nucleus surrounded by a membrane and other membrane-bound organelles
  • Protozoans are animal-like and ingest food or absorb food
  • Algae are plant-like, contain chlorophyll and make their own food by photosynthesis
• Fungi


  • Most are multicellular with a body composed of microscopic threads called hyphae, a few are unicellular
  • Cells have cell walls that contain chitin
  • Cells lack chlorophyll
  • Most reproduce by spores
  • Feed by absorbing food
• Plantae (plants)

  • Multicellular organisms
  • Cells have cell walls made of cellulose
  • Cells contain chlorophyll
  • Make their own food by photosynthesis
  • Stationary organisms
• Animalia (animals)


  • Multicellular organisms
  • Cells lack cell walls and chlorophyll
  • Feed by ingesting food
  • Most move their whole bodies from place to place
• Bryophytes


  • Have simple stems and leaves
  • Have root-like filaments called rhizoids
  • Produce spores for reproduction
  • Live in damp, shady places
• Ferns


  • Have proper roots, stems and leaves called fronds
  • Produce spores on the underside of fronds for reproduction
• Conifers


  • Have proper roots, stems and leaves
  • Produce seeds for reproduction
• Yeasts, moulds and mushrooms

  • Most are multicellular with a body composed of microscopic threads called hyphae, a few are unicellular
  • Cells have cell walls that contain chitin
  • Cells lack chlorophyll
  • Most reproduce by spores
  • Feed by absorbing food
• Yeasts, moulds and mushrooms

  • pin mould
• Plantae (plants)


  • Multicellular organisms
  • Cells have cell walls made of cellulose
  • Cells contain chlorophyll
  • Make their own food by photosynthesis
  • Stationary organisms
• Animalia (animals)


  • Multicellular organisms
  • Cells lack cell walls and chlorophyll
  • Feed by ingesting food
  • Most move their whole bodies from place to place
• Bryophytes


  • Have simple stems and leaves
  • Have root-like filaments called rhizoids
  • Produce spores for reproduction
  • Live in damp, shady places
• Bryophytes


  • moss, liverwort
• Ferns


  • Have proper roots, stems and leaves called fronds
  • Produce spores on the underside of fronds for reproduction