(Year 7 / 6th Gr) Living beings produce matter

Throughout their lives, living beings grow and develop. They do so by making their own matter (every little thing that constitutes their organs).

How matter production happens in « green plants » ?

I- The production of organic matter by plants

After germination, plants keep on growing and they increase in size. They become bigger and bigger, and therefore their mass increases. They develop by producing new organs (stems, leaves, roots, and so on).

The organs they produce are made of matter called « organic matter » (the living matter). The plants thus produce organic matter from matter removed from their environment.

Croissance de plantules de blé

Croissance de plantules de blé

How matter production happens in animals and fungi ?

II- The organic matter produced by animals and fungi

Animals grow and become bigger and bigger. They produce organic matter, used for their development (growth, pregnancy, coat, shell, milk …). Animals produce the aforesaid organic matter by feeding on other living beings (plants or animals). Therefore they use organic matter removed from their environment.

(Year 9 / 8th Gr) The earthquakes

What I’m looking for : what are the different earthquakes’ manifestations on the earth surface  ?
I- Earthquake’s effects on surface 
Earthquakes reveal themselves through ground’s violent vibrations and provoke damages and transformations on the surface of the earth (some faults take shape after an earthquake ). The place where an earthquake starts, and, where its intensity is stronger, is called the epicenter.
What I’m looking for : what are these vibrations that we feel during an earthquake ?
II- The origin of an earthquake ’s vibrations
The vibrations caused by an earthquake provoke some motions of the ground that we can observe and record with a seismograph. Those vibrations are seismic waves that spread very fast in all directions.
What I’m looking for : How seismic waves are created at the origin of drifts ?

III- The origin of an earthquake
There are constraints exerted on the rocks at depth. The stored energy eventually cause rupture of rocks that slide against each other causing the birth of seismic waves.
The point of initial rupture is called the earthquake’s focus. The epicenter is the point at ground level directly above the focus.

What I’m looking for : where are earthquake zones located on Earth ?

IV- The distribution of earthquakes
There are on Earth three great seismic zones. Earthquakes occur mainly in mountain ranges, near the ocean trenches and also along the axis of the ridges.