P16 C.ELEGANS

INTRODUCTION 

On the 15th of February we went to the PRBB, biomedical research park in Barcelona. There we did an activity that consisted in classifying some bugs (some worms called C. Elegans) according to the characteristics that they had (physical and genetic).

There were 4 small boxes:

- Wild C. elegans.
- GFP + RFP (fluorescence proteins)
- Daf 18 mutated (mutated gene, they had cut it so that C. Elegan was shorter).
- Daf 18 silenced (turn off a gene).

We divided into four groups (Microscopy, image, genetics and behaviour). One of our students went through the groups analysing what we were doing.

My group had the tasks of microscopy.

OBJECTIVES 

The aim of microscopy was to classify the C. Elegans from knowing that in the laboratories there are more hermaphrodites, so that they can reproduce better. Hermaphrodites have a pointed tail and the males have a round tail. 

PROCEDURE 

We take some microscopes and one magnifying glass to see the different boxes of c. elegans and we keep watching them and to check how many were males and hermaphrodites. We took notes in a paper. 

RESULTS 
These are the common results of all groups.

	TYPE (RESULT)	MICROSCOPY	IMAGE	GENETICS	BEHAVIOUR
A	DAF 18 mutated (FLUORESCENCE)	8 males 100 herma	I X F X	More shorter	More to the salt. (THEY SMELL)
B	GFP-RFP	All herma	I X F V	Long	More to the salt.(THEY SMELL)
C	WILD	6 males 100 herma	I X F X	Long	They go wherever they want.( THEY DON’T)
D	DAF 18 SILENCED	All herma	I X F X	Less long than the others	They go wherever they want. (THEY DON’T)

P15 OSMOSIS IN THE ONION

OBJECTIVE 

The aim of this practice is to observe the process of osmosis in the onion, as well as to see the plasmolysis and the turgor  of the plant cell in each case using salt and distilled water.

MATERIAL 

• Optical microscope 
• A slide and a cover slide
• Forceps
• A dropper  
• An onion 
• A knife 
• Distilled water
• Salt
• A  100mL beaker

PROCEDURE 

Peel the onion and cut two small pieces of the inside.

Prepare two optical microscopes.

Prepare a beaker with water and salt.

Make a sample with one of the pieces and add a few drops of salt water with the help of a dropper.

Cover it with the slide and coverslip, and watch it. In this case it is not necessary to dye it.

Then prepare another sample but this time adding drops of distilled water.

Cover and observe under a microscope.

RESULTS

The sample with salt is called hypertonic solution, so the cells are going to lose water and became smaller and tighter.

The sample with distilled water is an isotonic solution, so the cells are going to absorb water and became bigger and fatter. 

QUESTIONS 

   1. When the salt solution was added to the onion cells where was the greater concentration of water? The higher concentration of water will be outside of the cell, because of the hypertonic solution, the water will go outside to equal the concentration.

   2. Which kind of transport does water follow across the membrane? Active transport by simple diffusion.

P 14 COCA - COLA SUGARS

OBJECTIVES

We want to observe the quantity of sugars that we can find in different cool drinks. We also want to know if it is true that light drinks they do not carry sugar. 

MATERIAL 

• Test tube rack. 

• 2 test tubes.

• 2 Beaker 250 mL 

• Fehling A and Fehling B

• Wiro Gauze 

• Lab Burner

• Coca-Cola Light

• Coca-Cola 

PROCEDURE

Get two beakers and put in coca-cola in one and coca-cola light in the other.

Warm up them in a burner to concentrate the sugars.

Then put 5 mL of each of them in a test tube.

Add 2mL of Fehling A and 2 mL of Fehling B in both of them.

RESULTS 

CONCLUSIONS

Coca-cola light is negative, so it keeps in the colour blue and coca-cola is positive, it has reducing sugar, so it changes to colour brown. 

The glucids  are oxidized and they reduce the Copper Sulphate of Felhings (A and B). The Copper (++) is reduced to copper (+). We can observe it because the colour changes from blue to red-brown.
So we can say that coca-cola light don't carry sugars.