Form 4 Chapter 2 - Cell structure & cell organisation (part 2)

here are the recap from our previous lessons .....

1) Density of organelles in specific cells:

• example 1:
  Pancreatic cells have high density of rough ER & GA.
  because Pancreatic cells synthesise & secrete pancreatic juice (which contains enzyme) & hormone insulin.


• example 2:
  Palisade mesophyll cells of the green leaves have high density of chloroplast organelles.
  because PMC needs to absorb sunlight during photosynthesis.
  
• refer to your notes for more examples

2) Living processes of Unicellular organisms.

• We look at 2 unicellular org. (Amoeba sp. & Paramecium sp.) to study the 8 living processes listed below.
  

1. Feeding


2. Excretion


3. Growth


4. Locomotion


5. Sensitivity


6. Respiration


7. Reproduction


8. Osmoregulation

• Amoeba sp
  
  
  

1. Feeding - engulf foods through a process called phagocytosis. (you should know how to explain the process, including drawing of the labelled diagrams)







2. Locomotion - forming of pseudopodia through cytoplasmic projection.
   
3. Osmoregulation - carried out by contractile vacuole. (you shld know the explanation here)
   
4. Reproduction - only asexual reproduction - binary fission. (you should also know the drawing of labelled diagrams). spore formation.

• Paramecium sp

1. Feeding - beating the cilia to bring food particles to its oral groove, into the gullet & cytostome.
   
2. Locomotion - swimming through beating of cilia.
   
3. Osmoregulation - carried out by the 2 contractile vacuole. explanation....












4. Reproduction
   

• asexual reproduction - binary fission
  
• sexual reproduction - conjugation, where exchange of genetic materials occurs between 2 parameciums.
  
  
  
  
  
  

I look forward to meet you again in the next lesson. take care.