Topic 1

• Osmosis

  The movement of water molecules from across a partially permeable membrane from a region of high water concentration to a region of low water concentration
• To show osmosis

  1. Chop up equal potato cylinders and measure their mass

  2. Get some beakers with different sugar solutions in them

  3. Leave potato in beaker for 24 hours

  4. Take potato out, dry and measure mass

  5. If cylinders have drawn in water by osmosis, their mass would have increased. If water is drawn out, their mass would decrease
• Rate of water uptake is measured in percentage change in mass over time
• What is a eukaryotic cell?

  A cell with a nucleus
• What is a prokaryotic cell?

  A cell without a nucleus
• What is a cell?

  The smallest unit of life that can replicate independently
• What is the function of the cell membrane?

  Control what comes in and out of the cell
• What is the function of the nucleus?

  Contains DNA, controls activity of the cell
• What is the function of the cytoplasm?

  Holding organelles, where chemical reactions take place
• What is the function of the mitochondria?

  Provide cell with energy needed to function through aerobic respiration
• How do the mitochondria make energy?

  Through aerobic respiration, breaking down glucose
• What is the function on ribosomes?

  site of protein synthesis
• What is the cell wall made off?

  Cellulose
• What is the function of the cell wall?

  Provide Support and structure for cell
• What is the function of the permanent vacuole?

  Contains cell sap
• What is the function of chloroplasts?

  Photosynthesis
• What substance do chloroplast Contain?

  Chlorophyll
• What do bacteria cells never have?

  Chloroplasts, nucleus or mitochondria
• What are plasmids?

  Extra genes within a bacteria cell
• What are the three key stages of the cell cycle?

  . Growth

  . DNA replication + mitosis

  . Division ( cytokinesis)
• What are the Steps for mitosis?

  1.prophase-DNA condenses to form chromosomes

  2.metaphase-chromosomes line up on the equator (middle of the cell)

  3.anaphase-chromosomes get pulled to poles of cell (still moving)

  4.telophase-chromosomes stop moving once they get to poles

  5.cytokinesis-physical process of splitting into two
• What step in mitosis is anaphase and what does it mean?

  Step 3, chromosomes get pulled to poles of cell (still moving)
• What step in mitosis is prophase and what does it mean?

  Step 1, DNA condenses to from chromosomes
• What step in mitosis is cytokinesis and what does it mean?

  Step 5, physical process of splitting into two
• What step in mitosis is telophase and what does it mean?

  Step 4, chromosomes stop moving when they get to poles
• What step in mitosis is metaphase and what does it mean?

  Step 2, chromosomes line up in the middle of the cell
• What is mitosis?

  When a cell splits into two genetically identical daughter cells
• What do multicellular organisms use mitosis for?

  The grow and develop, or replace old cells that have been damaged
• How many steps of mitosis are there?

  5
• How many pairs of chromosomes do humans have?

  23
• How many chromosomes do humans have in total?

  46
• What step of mitosis is this?

  Metaphase

  
• What step of mitosis is this?

  Telophase

  
• What stage of mitosis is this?

  Cytokenisis

  
• What is binary fission?

  Process which prokaryotic organisms divide and reproduce
• Before a bacterial cell can divide it needs to do two things:

  1.grow

  2.replicate its DNA
• What are the steps to binary fission?

  1.The two circular strands of DNA move to opposite sides of the cell

  2.A new cell wall from down the middle of the cell

  3.The two halves pull apart to form two cells
• True or false binary fission takes a long time?

  false
• How do you calculate the amount of time a bacteria cell with divide within a certain period of time?

  1.calculate how many times the bacteria divides in that time

  2.calculate the number of bacteria in the population
• The mean division time for bacteria population A is 20 minutes. If the observation begins with one bacterium, calculate how many bacteria will be present after six hours?

  262,144