Wednesday, 24 August 2011

Biology - Life Processes, Cells, Amoeba

I am working from a book called Science KS3 Classbook by Terry Hudson.  It includes Biology, Chemistry and Physics. 


This first topic in the book is similar to what I did last year:


MRS NERG - 7 Life processes


Movement
Respiration
Sensitivity to environment
Nutrition
Excretion
Reproduction
Growth


Animal and plant cell diagrams





Image source:  waynesword.palomar.edu, http://chemistrybook2011.blogspot.com/2011/05/plant-cell-figures.html




Cell Organelles
Image source: http://www.tutorvista.com/biology/function-of-animal-cell




Differences between these two types of cells.


Animal Cell and Plant Cell Structures.


Image source: http://www.tutorvista.com/biology/function-of-animal-cell




AMOEBA


To read about amoeba - have a look at this site:  http://www.biology-resources.com/amoeba-01.html


Then we looked at how an Amoeba would carry out each of the 7 life processes.

  
M- move by flowing of cytoplasm over the surface i.e mud, soil.      
   - pseudopods - changing the shape of their body.
R-"breathes" using a porous cell membrane (oxygen in - carbon dioxide out)
S-  no special sense organs.
  - changes in outside world detected by all parts of living material
  - limited sensitivity e.g. moves away from light, but it has no photodetectors or eyes
N- food is engulfed by pseudopods (False foot) - forms a food vacuole.    
   - eat algae, bacteria, other protozoans, tiny particles of dead plant / animal matter
E- ingestion and egestion can take place at any point on the surface
   - no ‘mouth’ or ‘anus’.
R- a parent cell divides (Nucleus + cytoplasm divide)
   = two smaller daughter cells i.e. asexually by binary fission
G- grows from nutrition - digesting food.


Other links:  

(Oracle Think Quest - Projects by Students for Students)
Biology Teaching Resources  

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