Biology - cells

• Xylem cells function


  To transport water and dissolved minerals from the roots to the leaves
• Xylem cell adaptations


  contains lignin which kills the contents in the cell so that it's a long hollow tube, this allows water to flow with very little resistance.

  
  

  Lignin also strengthens the xylem wall which provides support to the stem
• Phloem cell function

  To transport the dissolved sugars produced in leaves.
• Phloem cell adaptations


  Cells are living so that food can move both up and down the plant

  
  

  Consists of long tubes to allow dissolved foods to travel
• Ciliated cell funtion

  The function of a ciliated cell is to protect the body from disease and infection
• Nerve cell function

  To carry electrical impulses through the body or brain
• Nerve cell adaptations

  Contains dendrites which make connections to other nerve cells

  
  

  Has a long axon to carry electrical impulses from one place to the other
• Root hair cell function

  Absorbs water and mineral ions from the soil
• Root hair cell adaptations

  Has a large surface area to absorb more water

  
  

  Has a large permanent vacuole which helps speed up the movement of water from the soil
• muscle cell function

  Contracts to bring about movement
• Muscles cell adaptations

  Contains ribosomes which are used to make special proteins

  
  

  Stores glycogen which can be broken down into glucose. The glucose can be used in respiration to release energy.
• Sperm cell function

  To carry genetic information from the male through the female reproductive tract to fertilise the egg cells in sexual reproduction
• Sperm cell adaptations

  Contains a tail called the flagellum that allows it to swim towards an egg cell

  
  

  Contains many mitochondria which provides energy from aerobic respiration so the cell can swim
• Red blood cell function

  transport oxygen and carbon dioxide through the body via the bloodstream
• Specialised cells

  Cells designed to carry out a particular role in the body
• What are the differences between prokaryotic and eukaryotic cells?

  prokaryotic cells do not have a nucleus or membranes
• Nucleus

  contains genetic material which controls the activities of the cell
• Cytoplasm

  Most chemical processes take place here, controlled by enzymes
• cell membrane

  Controls the movement of substances in and out of the cell
• Mitochondria


  Where aerobic respiration takes place
• Ribosomes

  Protein synthesis happens here
• Cell wall


  Strengthens the cell and maintains it's shape
• Chloroplast

  Contains chlorophyll which absorbs light energy for photo synthesis
• Permanent vacuole

  Filled with cell sap to help keep the cell turgid
• Differences between plant and animal cells

  Plant cells have chloroplasts, a cell wall, and vacuoles while animal cells do not.
• Why do muscle cells contain many mitochondria?

  To provide large amounts of energy to the muscle for contractions
• Organelle

  Structure in the cytoplasm of a cell that can carry out special tasks
• Cell

  The basic unit from which living things are made
• Tissue

  A group of specialised cells with similar structure and function
• Organ

  A group of different tissues working together to carry out a particular function
• Organ system

  group of organs that work together to perform a specific function
• Organism


  a living thing which can carry out the seven life processes
• What does the muscular tissue do

  Contracts to bring about movement
• What does glandular tissue do?

  Contains secretory cells that produce and release enzymes and hormones
• What does epithelial tissue do?

  Covers the outside of the body as well as your internal organs
• Epithelial tissue that occurs in surfaces Im the interior of the body is known as..

  Endothelium
• Formula for magnification


  Magnification = image size / real size
• Formula for image size

  Image size = magnification x real size
• Formula for actual size

  Actual size = Image size / Magnification
• Light microscope

  Low magnification and resolution, cheap, not as magnified images