Explosive Science

Looking back, it was sure a fun time learning science in HC, we learned so much about the science around us and Ms nada was indeed a very good teacher. It is almost a year now. The final year exams are coming and i got to study hard. I would like to thank Ms Nada for her support and her being such strong willed to teach us so many things about science. I would like to qute from Issac Newton( the guy who had an apple to fall on his head and found out GRAVITY) "I had seen further by standing on the shoulders of giants( Ms Nada) " Thank you Ms Nada for teaching me and my class 1P3 : )

Time for a quick history lesson :
In the mid-17th Century, biologist Jan Baptist van Helmat suspected that plant growth had to come from water, after test he conducted showed no change in soil amount. However, carbon rich organic molecules can be found in plants. Water does not provide carbon. Thus, from that point, scientists discovered that water was an important element for photosynthesis, but not the sole component. The process of making food was thus defined as photosynthesis. This was a step for man kind to finding out what was.....
PHOTOSYNTHESIS
It is a process which occurs only during the day. Carbon dioxide is taken in by the stomata, water by the roots and light trapped by chlorophyll to produce glucose and oxygen.


Chloroplast
- disc like structures found in the cytoplasm of a plant cell
- chlorophyll found stacked up in chloroplast
- leaves are green due to chloroplast which reflects green light.
Glucose
- food for the plant
- stored as starch in other parts such as in the root, potato
Stomata
- found mostly on the underside of a leaf to prevent water loss
- has two guard cells at the sides responsible of opening and closing of stomata
- allow gas exchange 


Here are some of the test you can do to find out if the leaf is making food(photosynthesising)

• Carbon dioxide bubbled through Calcium Hydroxide(lime water though now in sec 1 cannot be used), a white precipitate ( milky ) will be formed in the Calcium Hydroxide.

• Oxygen will relight a glowing splint
• Brighter glow is also counted as a presence of oxygen

• A variegated leaf is destarched(no light, kept in a dark room ) for 4 days, before boiled and soaked in ethanol to stop all chemical reaction within the leaf and decolourise it.
• Next, Iodine solution is dropped onto the leaf.
• If the leaf turns brown, Starch is absent.
• If it turns blue- black, Starch is present

Here is a website about the digestive system >> The digestive system

Diffusion and osmosis
Diffusion and osmosis occurs from "more to less"

• Small molecules consist of salt, water and glucose

• An Isotonic solution > is one with an equal water to solute concentration
• A Hyptotonic solution > is one with a higher concentration of water than the solution
• A Hypertonic solution > is one with a lower concentration of water than the solution
• 
  
• PLUS
• Animal Cells that have 
• too mush water - lysed
• same amount of water - normal 
• too little water - shrivelled
• 
  
• Plant Cells that have 
• too much water - turgid
• same amount of water - flaccid
• too little water - plasmolysed
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• 
  

Firstly we learned how to draw the cells of both plant and animal.
here is how we should draw and label :


The hardest part was trying to draw the circle and the rounded edge square without being able to see where we started and end. Ms Nada had a very sharp eyes and could easily see where we started and ended. It took me 5 attempts to be able to draw the perfect one. Practice makes perfect, so remember to keep drawing and drawing...

We also had a chance to scrap our own cheek cells and to see it under the microscope and it was so interesting. we also had to learn how to peel of a thin piece of  skin from the onion and view its plants cell under the microscope.

 is the required drawing of the different diagram.