B2

• active transport


  • requires energy
  • Movement of molecules against a concentration gradient
• What does the xylem do?

  Transport water and nutrients in plants.
• Features of xylem vessels 


  • Impermable due to cell wall of lignin

  •Provides support

  •Made of dead cells

  •One way flow of water and minerals
• What does phloem do?


  Transports glucose made in leaf by photosynthesis to other parts of plant
• Features of phloem vessels

  •Lots of mitochondria

  •Two way flow

  •Made of living cells
• How is the rate of transpiration measured?


  Potometer
• How is transpiration increased?

  Increased light

  Increased temperature

  Increased wind

  Decreased humidity
• What does mitosis produce?


  Two genetically identical daughter cells
• What are stem cells?

  Undifferentiated cells that have the ability to develop into different types of specialized cells in the body.
• What are stem cells used for?

  Growth and repair
• Feature of a sperm cell


  A tail to allow it to move
• Feature of a xylem cell


  Long, thin hollow cells to transport water
• Feature of an ovum cell


  Large to carry food for developing embryo
• Feature of root hair cell


  Tiny hair like extensions to increase surface area for absorption
• Feature of a nerve cell 


  Long, slender axons to carry impulses
• Where are stem cells in plants 


  Meristems
• Where are stem cells in adults 


  Body tissue e.g bone marrow
• Where are stem cells in embryonic 


  Embryo
• What is osmosis?


  movement of water molecules from an lower concentration to higher concentration across a semi-permeable membrane.
• What does an increased surface area : volume ratio do?


  Speeds up diffusion
• What is diffusion?


  movement of particles from high concentration to low concentration.
• What type of transport is diffusion?


  Passive
• How is diffusion increased?

  Increased concentration gradient and surface area

  Short diffusion distance
• What do white blood cells do?


  Fight infections
• What do red blood cells do?


  Transport oxygen
• What does plasma do?

  Plasma carries nutrients, hormones, and waste products throughout the body.
• How thick is a capillary?

  One cell
• Where do veins take blood?


  Toward the heart
• Does a vein or an artery have a large lumen?

  A vein
• What stops backflow in viens 


  Valves
• Where do artery’s take blood 


  Away from the heart
• Why do artery have thick walls?


  High pressure