Study this example situation: I’m working.please be quiet.This mean: I’m working now, at the time of speaking.The action is not finished. Am/is/are + –ing is the present continuous: I am doing something = I’m in the middle of doing it, I’ve started doing it and I haven’t finished: The weather is nice at the moment […]
Posts from May 2015
Chapter 11 : specific features of meiosis
Meiosis has three unique features : The mechanism of cell division varies in important details in different organism. This is particularly true of chromosomal separation mechanism, which differ substantially in protists and fungi from the process in plants and animals that we will describe here. Meiosis in a diploid organism consists of two rounds of […]
Chapter 10 : meiosis
The sequence of events during meiosis involves two nuclear divisions ( meiosis I and meiosis II ). Prophase 1 In prophase 1 of meiosis, the DNA coils tighter, and individual chromosomes first become visible under the light microscope as a matrix of fine threads. Because the DNA has already replicated before the onset of meiosis, […]
Leçon 1 : le présent
Le présent de l’indicatif est utilisé pour : 1) Exprimer un fait qui se déroule au moment où on le rapporte : -je mange mon sandwich. – J’écris une lettre. – Je conduis ma voiture. 2) Exprimer une action qui dure : – tu étudies le français depuis un mois. – tu habites à Bruxelles depuis […]
Chapter 4e: Phase diagram
The state of compounds depends on the temperature and on the pressure. We map the states of the matter on the diagram of phases. The pressure is put as ordinate and the temperature as abscise. The states are separated by full lines, the curves of transition of phase. The curve between the liquid and the […]
Chapter 4d: Solids – lattice energy
In gases, the heat capacity was a resultant of translation, vibration and rotation. In a solid, there is no translation and no rotation. The atoms may vibe around their equilibrium position. The vibration involves a potential energy and a kinetic energy, each term participating for ½R. As a solid has 3 dimensions, Cv=3R However, this […]
Chapter 4c: Solids – crystallography
A characteristic of the solids is that they have their own shape. Liquids are taking the shape of their recipient and gases take all the available space. So solids have their own shape but some are malleable, can be cut, be creased or smashed or can be very rigid. As explained at the beginning of […]