Monday, February 7, 2011


Cells

1.Each cell is made up of protoplasm
2.protoplasm like:
   - cell membrane
   - cytoplasm
   - nucleus

Both animal and plant cells have protoplasm (e.g cell membrane,cytoplasm and nucleus)
                                                    organelles (e.g mitochomdria and vacuoles)

The different functions
 cell membrane
  • it is partically membrane
  • controls the movements in and out of the cell
  • it only allows water and oxygen into the cell
  • removes waste (e.g carbon dioxide)
Cytoplasm
  • it stores, transports materials and produces things in the cell
Nucleus
  • contains chromosomes made up of DNA
  • DNA controls all activities in the cell
 Mitochondria
  • produces energyduring respiration
vacuoles
  • stores and transports products
  • keeps excess water
cell wall
  • helps to keep its shape
  • protect it from external factors
  • prevent it from bursting
Chloroplast
  • contains chlorophyll
  • responsible for producing food
  • a process called photosynthesis
Next the root hair cell, this cell helps to absorp water and mineral salts.

Following xylem vessel, they transport water and mineral salts. xylem vessels also provide support.
xylem vessels are non-living thins and are hollow.

Lastly red blood cells, they are responsible for transporting water. Red blood cells contain haemoglobin. They have got a biconcaved shape. Red blood cells too does not have a nucleus and can be easily folded, allowing them to squeeze through blood capillaries.






































































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