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• Root hair cells are specialised cells. Describe how the root hair is adapted to carry out its function.


  Had a large surface area for the rapid absorbtion of water and mineral ions from the soil.
• What organelle of a plant cell is the site of anaerobic respiration?


  cytoplasm
• what organelle of a plant cell is the site of protein synthesis?


  ribosomes
• What organelle in a plant cell is the site of photosynthesis?


  chloroplasts
• Sperm cells are specialised cells. Explain how the acrosome helps carry out the sperm cell to carry out its function

  The acrosome contains enzymes to digest through the egg cell membrane
• How many chromosomes does:

  a human skin cell contain?

  a human gamete contain?


  46/23 pairs (diploid)

  23 single (haploid)
• why do cells undergo mitosis?


  To produce new cells for growth and repair
• What happens to the cell during interphase?

  The cell grows increases the amount of organelles and replicates its DNA
• What happens to the cell during mitosis?

  1.Chromosomes line up at the centre of the cell and the copies are pulled apart by spindle fibres to opposite ends of the cell

  2. Nuclear membranes form around the chromosomes to make 2 nuclei

  3. Finally the cell splits into two identical ‘daughter‘ cells.
• What are “embryonic”stem cells ?

  Undifferentiated cells found in the early embryo
• Name 2 medical conditions that could be treated with embryonic stem cells in the future.

  1. Diabetes
  2. Spinal injuries/paralysis
• Describe how to prepare an uncontaminated culture of bacteria using the aseptic technique.

  sterilise the Petri dish
• Diffusion is…


  The spreading out of any gas or liquid from an area of high concentration to an area of lower concentration
• Name 3 substances that are transported into or out of animal cells by diffusion:

  1.Oxygen

  2.carbon dioxide

  3.amino acids
• Describe an advantage of using therapeutic cloning to treat disease

  The stem cells would have the same DNA as the patient so would not be rejected by the body
• What is osmosis?


  The movement of water molecules from an area of high water concentration to an area of lower water concentration across a partially permeable membrane.
• Light microscopes have objective lenses.

  what is the purpose of the objective lens?

  To form and magnify an image of the specimen.
• Name the plant that transport water up the stem of a plant

  Xylem
• Which organelle of a animal cell is the site of aerobic respiration?

  Mitochondria
• What organelle of a animal cel controls the movement of substances in and out of the cell

  Cell membrane
• What organelle of a plant cell contains the genetic information

  Nucleus
• Root hair cells are specialised cells. Describe how the root hair fell so adapted to carry out its function. 


  has a large surface area for the rapid absorption of water and mineral ions from the soil
• Describe how active transport is used by plants

  To obtain mineral ions from the soil
• Describe how active transport is used by animals

  To absorb nutrients(e.g glucose) when they are at low concentrations from the small intestine
• Describe 3 ways that exchange surfaces are adapted to their function

  1.large surface area

  2.thin walls

  3.moist/good blood supply (animals)
• Describe 2 ways active transport is different to diffusion

  1. moves against a concentration gradient (low to high)
  2. requires energy
• Where in the body are adult stem cells found and how do they differ from embryonic stem cells?

  found in the bone marrow. Can only turn into certain cell types such as blood vessles
• What do each represent

  mm:

  millimetres
• µm

  Micrometers
• nm

  nanometers
• Pm

  Picometers
• Plants can be cloned from meristem cells. give two advantages of cloning plants

  Farmers can produce clones of desired plant quickly and cheaply. Save rare species from extinction
• Electron microscopes have better resolution than light microscopes. What does resolution mean?


  The ability to distinguish between 2 points so higher resolution produces a clearer image.
• State two factors that affect the rate of diffusion

  1.temperature

  2.concentration gradient
• What is the equation for calculating the magnification of an image?

  Magnification = image size/real size
• How do prokaryotic cells differ from eukaryotic cells?

  Bacterial cells are much smaller they don’t have a nucleus they don’t have mitochondria or chloroplats.
• Why do some people object to embryonic stem cell research

  They believe that embryos have the potential to become a human being so should not be used for experimentation