Year 8 work on owl pellets

Year 8 have been dissecting owl pellets. This will help them to know what the owl has been eating.

 The owl pellet is made of the bones and fur that the owl has swallowed

The owl coughs up these pellets rather than them going through the whole digestive system 

The pellets need soaking so they can break apart easily 

 Then the bones need to be separated from the fur

and washed  

Careful work is required so the delicate bones are not broken.  

The bones will now be soaked in bleach solution 

This cleans up the bones and kills any bacteria on them.

Testing a BigMac

Today 7C started their new topic Digestion and Nutrition with an experiment to test a BigMac for nutrients.

The BigMac was split into its component parts

so they can be tested

Testing with sodium hydroxide and copper sulphate 

to see if there is any protein 

Care must be taken with the sodium hydroxide, a strong alkali, as it is corrosive.

Using ethanol to extract the fat from food 

once filtered the solution will  

turn cloudy when drops of water are added

if it contains fat. Then record the result

 Iodine shows the presence of starch by turning from orange, brown to blue, black

 Benedict's solution turns from blue to green, orange or red if there is glucose in the food.

Lots of accurate testing 

means we now know......

 

Well, you will have to wait for the final report. 

 

 

 

 

 

 

6S on microscopic safari

6S used their newly gained microscopy skills to look for single celled organisms in a moss clump
you can follow this link to see a short film on vimeo

Protoctista from Brambletye on Vimeo.

It was taken by pointing an iPhone down a microscope. My apologies for the not brilliant quality but I hope you find the subject matter interesting.

Year 7 Examine DNA

Not quite Silent Witness but we have extracted the DNA from an onion during our work on reproduction.

First get your equipment ready 

and read the instructions 

 

mix the onions with salt water

 

and grind together to crush the cells and dissolve the DNA 

the more its ground the better 

 

Then we need to filter the insoluble onion out of the mixture

We use cloth to filter the insoluble bits

The residue stays in the filter funnel 

The filtrate passes through into the measuring cylinder

 

We have to collect 50ml

 

 

 

 

 

Then we add washing up liquid to the filtrate 

this must be stirred in carefully as we don't want any froth

One class recorded their experiment photographically using the ipad 

Careful mixing

 

Just one spoonful

 

 

 

Now we need cold ethanol

This must be poured in carefully 

down the edge of the beaker

 

so that the ethanol floats on top of the solution

 if you are careful enough

then you get two distinct layers 

with a sort of white fluffy boundary 

this white stuff is the DNA 

which looks stringy 

well there is about 1m length of it in each cell! 

The DNA is the middle layer here