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Cell structure and organisation

1.1  Plant Cells and Animal Cells:

Fig.1.0 Basic structures of an animal cell and a plant cell.

1 . Cell wall:

  • Porous.
  • Permeable.
  • Non-living structure made of cellulose.

2 . Cell membrane/Plasma membrane

  • Semi-permeable/Partially permeable(Only certain parts can pass through it and some aren’t able).

3 . Cytoplasm

  • Contains cell organelles.
  • Food substances.
  • Mostly H2O.

4 . Vacuole/Sap vacuole/Large central vacuole

  • Mostly H2O.

5 . Nucleus

  • Controls all activities of a cell.

6 . Chloroplasts

  • Contains green pigment called Chlorophyll which is important for doing Photosynthesis.

7 . Differences between plant cells and animal cellsOnly plant cells have

  • Only plant cells have cell wall.
  • Only plant cells have chloroplasts.
  • Plant cells have a large central vacuole while some animal cells have small vacuoles and some doesn’t have any.
  • Plant cells have a regular shape while animal cells have irregular shape

1.2 Specialized/Modified cells:

1 . Root Hair Cell:

  • To absorb water and minerals
  • Finger-like projection:
  • Increases surface area for absorption.
  • Has a larger vacuole to store more H2O

Fig.1.2 Root hair cell.

 

2 . Red blood cell:

  • To carry/transport oxygen.
  • Packed with haemoglobin (red pigment).
  • No nucleus.
  • Biconcave shape

Fig.1.3 Red blood cells.

 

3 . Xylem vessels:

  • To transport H2O and minerals.
  • Supporting plant body

Fig.1.4(a)Whole plant, (b) plant stem and (c)xylem vessel

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