biology

• Cells are the basic units of all living things
• The two fundamentally different types of cells are animal and plant
• Some common structures shared by plant and animal cells include: the cell membrane, cytoplasm, DNA, and ribosomes
• Prokaryotic cell:

  • Organisms made up of a single cell
  • Have no distinct nucleus
  • No membrane-bound organelles
  • Cell walls made of peptidoglycan
• Eukaryotic cell:

  • Organism consisting of a cell or cells
  • DNA in the form of chromosomes contained within a distinct nucleus
  • Larger and more complex than prokaryotes
  • Have many different membrane-bound organelles
  • DNA is in the form of linear chromosomes contained in the nucleus
  • Cells are surrounded by a cell wall composed of carbohydrates
• Levels of organization:

  • Double helix made up of base pairs
  • Adenine, Guanine, Thymine, Cytosine
  • DNA is deoxyribonucleic acid
  • Gene is a sequence of DNA that codes for a particular trait
  • Chromosome is an organized package for an organism
  • Organelles are parts of cells that perform specific functions e.g. nucleus
• CELL:

  • Building blocks of all living things
  • Living Things
  • Metabolize
  • Reproduce
  • React
  • Move
  • Grow
• Tissue:

  • A group of cells coordinating for a common purpose e.g. muscle tissue
• Organ:

  • A group of tissue coordinating for a common purpose e.g. kidney
• Organ system:

  • Two or more organs coordinating for a common purpose e.g. digestive system
• Organism:

  • A living thing
• Population:

  • A group of the same organisms living together
• Ecosystem:

  • All abiotic and biotic factors within a defined area
• Microscope magnifications:

  • Eyepiece magnification always = 10x
  • Low power magnification = 4x X 10x = 40x
  • Medium power magnification = 10x X 10x = 100x
  • High power magnification = 40x X 10x = 400x
  • Moving the slide right will move it left through the microscope, and the same for up and down (opposite directions)
• Rules for drawing scientific diagrams:

  • Use pencil
  • Draw simple 2D images
  • No sketchy lines
  • Include the magnification and scale bar
  • Only draw what you see
  • Label everything you draw
  • Keep the proportions realistic
  • Magnification = image size divided by the actual size
  • Resolution is the quality of the image
  • Specimens can be made clearer by staining them and by preparing very thin sections so light can get through them
• Diffusion is the movement of molecules from an area of high concentration to an area with a lower concentration
• Diffusion is a passive process as it does not require the input of energy
• Simple diffusion involves small uncharged molecules or lipid-soluble molecules passing between phospholipids to enter or leave the cell, moving from areas of high concentration to areas of low concentration (down their concentration gradient)
• Facilitated diffusion is the passive movement of molecules along the concentration gradient, where the membrane selectively allows only certain molecules and ions to pass through
• Factors affecting the rate of diffusion: concentration, temperature, and particle size. A higher difference in concentration, higher temperature, and smaller particle size speed up diffusion
• Osmosis is the net diffusion of water molecules across a semipermeable membrane
• A semipermeable membrane is a thin biological sheet of material that allows certain molecules to pass through more easily than others
• Hypotonic


  Less concentrated solutions when comparing two solutions
• Hypertonic


  More concentrated solution when comparing two solutions
• Isotonic


  Solutions that have the same concentration
• Active transport

  The movement of particles to a place of higher concentration through the use of energy, which the particles move against a concentration gradient
• which vesicular transport engulfs large particles?

  phagocytosis