Biology

• Cell


  Basic structural unit of life
• All living things are made up of cells
• A cell is not visible with the naked eye
• Light microscope


  Used to observe cells
• Animal cell


  • Irregular in shape
  • Consists of cell membrane, cytoplasm, nucleus
• Plant cell


  • Regular in shape
  • Consists of cell wall, cell membrane, nucleus, cytoplasm, vacuole, chloroplast
• Similarities between plant and animal cells

  • Both have a nucleus
  • Both have a cell membrane
• Differences between plant and animal cells

  • Plant cell is regular in shape
  • Plant cell has a cell wall
• Cell membrane

  • Thin boundary surrounding the cell
  • Controls the movement of substances into and out of the cell
• Cytoplasm


  Jelly-like substance where chemical reactions occur
• Nucleus

  Contains the genetic material and plays a role in heredity
• Vacuole


  Sac-like structure that stores water, food, salts and waste
• Chloroplast


  Contains the green pigment chlorophyll and traps light for photosynthesis
• Cell wall


  • Rigid structure surrounding the plant cell
  • Gives support, protection and shape to the plant cell
• Stains such as methylene blue and iodine solution are used to stain plant cells so that we can see the different parts of the cells
• A cell is the basic unit of living things
• Examples of different types of cells

  • Animal cell
  • Plant cell
  • Muscle cell
  • Red blood cell
  • Xylem cell
  • Epidermal cell
  • White blood cell
  • Phloem cell
  • Connective cell
• Groups of organs work together to form an organ system to carry out a specific action
• Examples of organ systems in animals

  • Digestive system (mouth, stomach, intestine)
  • Respiratory system (nose, windpipe, lungs)
  • Reproductive system
• Examples of organ systems in plants

  • Transport system
• Characteristics of living things

  • Movement
  • Respiration
  • Sensitivity
  • Reproduction
  • Excretion
  • Nutrition
  • Growth
• Movement


  • Animals can move from one place to another and move their entire body (locomotion)
  • Plants cannot move from one place to another but parts of the plant can move (e.g. mimosa plant, sunflower)
• Respiration


  • Process of breaking down food to produce energy
  • Oxygen is needed and carbon dioxide is released
• Excretion


  • Removal of waste substances from the body
  • Examples: carbon dioxide, urea, sweat
• Nutrition


  • Living things need food containing nutrients for proper body functioning
  • Plants manufacture their own food by photosynthesis
  • Animals feed on other organisms
• Mitochondria produce energy through aerobic respiration.