Biology Unit 1

• Cell


  The building blocks of living things, the simplest parts of an organism
• Levels of biological organisation

  1. Cells

  2. Tissues

  3. Organs

  4. Systems

  5. Organism
• Animal cell structure


  • Plasma membrane
  • Cytoplasm
  • Nucleus
  • Nucleolus
  • Ribosomes
  • Rough endoplasmic reticulum
  • Smooth endoplasmic reticulum
  • Vesicles
  • Golgi apparatus
  • Lysosomes
  • Centrioles
  • Mitochondria
• Plasma membrane


  Protects the cell, allows substances in and out
• Cytoplasm


  Liquid jelly with dissolved substances and chemical reactions
• Nucleus


  Control centre of the cell, surrounded by double membrane with pores
• Nucleolus


  Region in nucleus where ribosomes are made
• Ribosomes


  Make proteins, given instructions from DNA
• Rough endoplasmic reticulum


  Flattened sacs covered in ribosomes, making lots of protein
• Smooth endoplasmic reticulum


  Tube-like structures where lipids are made
• Vesicles


  Small membrane-bound sacs for storing and transporting substances
• Golgi apparatus


  Modifies proteins and packages them in vesicles for transport
• Lysosomes


  Contain digestive enzymes to destroy old organelles and pathogens
• Centrioles


  Involved in cell division, make the spindle
• Mitochondria


  Where respiration happens, produce ATP, have their own ribosomes and DNA
• Cells


  The basic unit of life and the smallest level of organization that can perform all the functions necessary for life.
• Tissues


  Groups of similar cells that work together to perform a specific function. There are four main types of tissues in the human body: epithelial, connective, muscle, and nervous.
• Organs


  Structures composed of two or more types of tissues that work together to perform a specific function. Examples include the heart, lungs, and stomach.
• Systems


  A group of organs that work together to perform a specific function. There are 11 major systems in the human body, including the circulatory, respiratory, and digestive systems.
• Organism


  A living being that has a distinct and independent existence. It is the highest level of biological organization and is made up of one or more systems.