Archivo de la categoría: biology

Testing inspired and expired air

Two weeks ago in the lab, we made a practical which considered on testing the effect of inspired and expired air on different things. This is the entry on the teacher’s blog ( and these are my results and analysis.

Blowing onto the thermometer:

The temperature rose from 25 degrees to 30 degrees. This was because of the heat our breath has.

Exhale onto the mirror

A kind of fog was formed in the mirror because of the heat our breath has that leads to the production of a sort of vapor when it gets into contact with an object such as a mirror.

Blow into limewater 

The test tube were the lime water was, was filled with a vapor due to the contrast between our breath and a cold surface such as glass.

Blow onto the glowing splint

Unluckily, in my group we didn’t get to blow into the wooden splint so we weren’t able to finish the practical. However I believe that if we had kept on blowing, we would have provided the fire with oxygen so at least a small flame would have been kept glowing.

Dissecting a heart

Some weeks ago, at the lab, the teacher brought a cow’s heart for us to dissect. The first thing we did was cutting it open and spotting the coronary arteries, the pulmonary artery, the valves, the vena cava, the aorta, the pulmonary vein, the ventricles and the atria. Then, we were able to cut it through the septum without rupturing any tendon. Once we had the two halves, we analysed them in depth and made a biological drawing.

Biology Practical 18/7

In our last class at the lab, we worked on a practica which consisted in watching our teeth with a mirror and then making a biological drawing of them. After that, some class mates used a mouthwash to check if they had any plaque. If they had plaque, their teeth would turn blue, if they didn’t nothing would happen.