Useful Information

The genome: What is a karyotype?

A karyotype is the study of the chromosomes of an organism. For this, cells are removed and the cell division is stopped at a stage that allows to observe the chromosomes well. Modern techniques make it possible to see if genetic alterations exist and which ones.

The study of chromosomes is quite often used. As for example, during a pregnancy, if we fear a chromosomal abnormality in the future baby, a sample of some fetal cells can achieve a karyotype. This is done by removing fetal cells from the amniotic fluid (by amniocentesis), we can now sometimes perform this cell harvest by taking blood from the mother and extract fetal cells passed into the bloodstream of the mother. The karyotype makes it possible to study the chromosomes in the fetus and to search, for example, for trisomy 21.

Do all the cells of the same individual have the same genome?


Yes, all cells have the same genome, with a few details. However, it is not expressed in the same way. For example, insulin is only secreted by the pancreas while growth hormone is secreted by a gland called the pituitary gland, located in the brain. Because the genes, yet identically present in all cells, are ordered to be locked or to express themselves according to the cells in which they are located.

Author: Ladane Azernour Bonnefoy, geneticist.
Expert consultant: Professor Bernard Dujon, Pierre and Marie Curie University and Institut Pasteur (Paris).

Popular Posts

Category Useful Information, Next Article

Healing - Useful Information
Useful Information

Healing

Healing is the physiological phenomenon that allows tissues to rebuild after a wound (injury, burn , surgery, trauma, etc.). The healing process follows a slow evolution, sometimes unpredictable, that can last up to two years ... The healing of skin tissue can be painful, or can leave unsightly problems
Read More
The homeo kit of the summer: Against the fever - Useful Information
Useful Information

The homeo kit of the summer: Against the fever

Possibility of combining a homeopathic medicine and a paracetamol-based medicine. Aconitum Napellus 9 CH (5 granules every hour and then space according to improvement): sudden onset fever, high, no sweat, with agitation and anxiety. Belladonna 9 CH (5 granules every hour and then space according to improvement): erratic installation fever, high, with sweats, with delirium
Read More
Blood donation: Conditions of blood donation - Useful Information
Useful Information

Blood donation: Conditions of blood donation

Here are the conditions necessary to donate blood in France: > Age: between 18 and 70 years old (between 18 and 50 years old for a donation of white blood cells). > Weight: it is necessary to weigh a minimum of 50 kilograms, because the law prohibits to collect more than 8ml / kg. The minimum volume of a blood donation is 400ml
Read More
The tiger mosquito: what to do when we see one? - Useful Information
Useful Information

The tiger mosquito: what to do when we see one?

But what to do when you see a tiger mosquito? In addition to these actions carried out by our public authorities, it is also up to everyone to be vigilant. The tiger mosquito breeds in small puddles of water. It is therefore necessary to avoid leaving stagnant water within reach. To do this, think of emptying each week the saucers of flower pots or any other container collecting water (the tiger mosquito can lay 200 eggs that will become larvae, then mosquitoes, after 7 days)
Read More